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1 /*
2 * fs/cifs/file.c
3 *
4 * vfs operations that deal with files
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2010
7 * Author(s): Steve French (sfrench@us.ibm.com)
8 * Jeremy Allison (jra@samba.org)
9 *
10 * This library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published
12 * by the Free Software Foundation; either version 2.1 of the License, or
13 * (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 * the GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24 #include <linux/fs.h>
25 #include <linux/backing-dev.h>
26 #include <linux/stat.h>
27 #include <linux/fcntl.h>
28 #include <linux/pagemap.h>
29 #include <linux/pagevec.h>
30 #include <linux/writeback.h>
31 #include <linux/task_io_accounting_ops.h>
32 #include <linux/delay.h>
33 #include <linux/mount.h>
34 #include <linux/slab.h>
35 #include <linux/swap.h>
36 #include <asm/div64.h>
37 #include "cifsfs.h"
38 #include "cifspdu.h"
39 #include "cifsglob.h"
40 #include "cifsproto.h"
41 #include "cifs_unicode.h"
42 #include "cifs_debug.h"
43 #include "cifs_fs_sb.h"
44 #include "fscache.h"
45
46
47 static inline int cifs_convert_flags(unsigned int flags)
48 {
49 if ((flags & O_ACCMODE) == O_RDONLY)
50 return GENERIC_READ;
51 else if ((flags & O_ACCMODE) == O_WRONLY)
52 return GENERIC_WRITE;
53 else if ((flags & O_ACCMODE) == O_RDWR) {
54 /* GENERIC_ALL is too much permission to request
55 can cause unnecessary access denied on create */
56 /* return GENERIC_ALL; */
57 return (GENERIC_READ | GENERIC_WRITE);
58 }
59
60 return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
61 FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
62 FILE_READ_DATA);
63 }
64
65 static u32 cifs_posix_convert_flags(unsigned int flags)
66 {
67 u32 posix_flags = 0;
68
69 if ((flags & O_ACCMODE) == O_RDONLY)
70 posix_flags = SMB_O_RDONLY;
71 else if ((flags & O_ACCMODE) == O_WRONLY)
72 posix_flags = SMB_O_WRONLY;
73 else if ((flags & O_ACCMODE) == O_RDWR)
74 posix_flags = SMB_O_RDWR;
75
76 if (flags & O_CREAT) {
77 posix_flags |= SMB_O_CREAT;
78 if (flags & O_EXCL)
79 posix_flags |= SMB_O_EXCL;
80 } else if (flags & O_EXCL)
81 cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
82 current->comm, current->tgid);
83
84 if (flags & O_TRUNC)
85 posix_flags |= SMB_O_TRUNC;
86 /* be safe and imply O_SYNC for O_DSYNC */
87 if (flags & O_DSYNC)
88 posix_flags |= SMB_O_SYNC;
89 if (flags & O_DIRECTORY)
90 posix_flags |= SMB_O_DIRECTORY;
91 if (flags & O_NOFOLLOW)
92 posix_flags |= SMB_O_NOFOLLOW;
93 if (flags & O_DIRECT)
94 posix_flags |= SMB_O_DIRECT;
95
96 return posix_flags;
97 }
98
99 static inline int cifs_get_disposition(unsigned int flags)
100 {
101 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
102 return FILE_CREATE;
103 else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
104 return FILE_OVERWRITE_IF;
105 else if ((flags & O_CREAT) == O_CREAT)
106 return FILE_OPEN_IF;
107 else if ((flags & O_TRUNC) == O_TRUNC)
108 return FILE_OVERWRITE;
109 else
110 return FILE_OPEN;
111 }
112
113 int cifs_posix_open(char *full_path, struct inode **pinode,
114 struct super_block *sb, int mode, unsigned int f_flags,
115 __u32 *poplock, __u16 *pnetfid, unsigned int xid)
116 {
117 int rc;
118 FILE_UNIX_BASIC_INFO *presp_data;
119 __u32 posix_flags = 0;
120 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
121 struct cifs_fattr fattr;
122 struct tcon_link *tlink;
123 struct cifs_tcon *tcon;
124
125 cifs_dbg(FYI, "posix open %s\n", full_path);
126
127 presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
128 if (presp_data == NULL)
129 return -ENOMEM;
130
131 tlink = cifs_sb_tlink(cifs_sb);
132 if (IS_ERR(tlink)) {
133 rc = PTR_ERR(tlink);
134 goto posix_open_ret;
135 }
136
137 tcon = tlink_tcon(tlink);
138 mode &= ~current_umask();
139
140 posix_flags = cifs_posix_convert_flags(f_flags);
141 rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
142 poplock, full_path, cifs_sb->local_nls,
143 cifs_remap(cifs_sb));
144 cifs_put_tlink(tlink);
145
146 if (rc)
147 goto posix_open_ret;
148
149 if (presp_data->Type == cpu_to_le32(-1))
150 goto posix_open_ret; /* open ok, caller does qpathinfo */
151
152 if (!pinode)
153 goto posix_open_ret; /* caller does not need info */
154
155 cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
156
157 /* get new inode and set it up */
158 if (*pinode == NULL) {
159 cifs_fill_uniqueid(sb, &fattr);
160 *pinode = cifs_iget(sb, &fattr);
161 if (!*pinode) {
162 rc = -ENOMEM;
163 goto posix_open_ret;
164 }
165 } else {
166 cifs_fattr_to_inode(*pinode, &fattr);
167 }
168
169 posix_open_ret:
170 kfree(presp_data);
171 return rc;
172 }
173
174 static int
175 cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
176 struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,
177 struct cifs_fid *fid, unsigned int xid)
178 {
179 int rc;
180 int desired_access;
181 int disposition;
182 int create_options = CREATE_NOT_DIR;
183 FILE_ALL_INFO *buf;
184 struct TCP_Server_Info *server = tcon->ses->server;
185 struct cifs_open_parms oparms;
186
187 if (!server->ops->open)
188 return -ENOSYS;
189
190 desired_access = cifs_convert_flags(f_flags);
191
192 /*********************************************************************
193 * open flag mapping table:
194 *
195 * POSIX Flag CIFS Disposition
196 * ---------- ----------------
197 * O_CREAT FILE_OPEN_IF
198 * O_CREAT | O_EXCL FILE_CREATE
199 * O_CREAT | O_TRUNC FILE_OVERWRITE_IF
200 * O_TRUNC FILE_OVERWRITE
201 * none of the above FILE_OPEN
202 *
203 * Note that there is not a direct match between disposition
204 * FILE_SUPERSEDE (ie create whether or not file exists although
205 * O_CREAT | O_TRUNC is similar but truncates the existing
206 * file rather than creating a new file as FILE_SUPERSEDE does
207 * (which uses the attributes / metadata passed in on open call)
208 *?
209 *? O_SYNC is a reasonable match to CIFS writethrough flag
210 *? and the read write flags match reasonably. O_LARGEFILE
211 *? is irrelevant because largefile support is always used
212 *? by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
213 * O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
214 *********************************************************************/
215
216 disposition = cifs_get_disposition(f_flags);
217
218 /* BB pass O_SYNC flag through on file attributes .. BB */
219
220 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
221 if (!buf)
222 return -ENOMEM;
223
224 if (backup_cred(cifs_sb))
225 create_options |= CREATE_OPEN_BACKUP_INTENT;
226
227 oparms.tcon = tcon;
228 oparms.cifs_sb = cifs_sb;
229 oparms.desired_access = desired_access;
230 oparms.create_options = create_options;
231 oparms.disposition = disposition;
232 oparms.path = full_path;
233 oparms.fid = fid;
234 oparms.reconnect = false;
235
236 rc = server->ops->open(xid, &oparms, oplock, buf);
237
238 if (rc)
239 goto out;
240
241 if (tcon->unix_ext)
242 rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
243 xid);
244 else
245 rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
246 xid, fid);
247
248 out:
249 kfree(buf);
250 return rc;
251 }
252
253 static bool
254 cifs_has_mand_locks(struct cifsInodeInfo *cinode)
255 {
256 struct cifs_fid_locks *cur;
257 bool has_locks = false;
258
259 down_read(&cinode->lock_sem);
260 list_for_each_entry(cur, &cinode->llist, llist) {
261 if (!list_empty(&cur->locks)) {
262 has_locks = true;
263 break;
264 }
265 }
266 up_read(&cinode->lock_sem);
267 return has_locks;
268 }
269
270 struct cifsFileInfo *
271 cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
272 struct tcon_link *tlink, __u32 oplock)
273 {
274 struct dentry *dentry = file_dentry(file);
275 struct inode *inode = d_inode(dentry);
276 struct cifsInodeInfo *cinode = CIFS_I(inode);
277 struct cifsFileInfo *cfile;
278 struct cifs_fid_locks *fdlocks;
279 struct cifs_tcon *tcon = tlink_tcon(tlink);
280 struct TCP_Server_Info *server = tcon->ses->server;
281
282 cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
283 if (cfile == NULL)
284 return cfile;
285
286 fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
287 if (!fdlocks) {
288 kfree(cfile);
289 return NULL;
290 }
291
292 INIT_LIST_HEAD(&fdlocks->locks);
293 fdlocks->cfile = cfile;
294 cfile->llist = fdlocks;
295 down_write(&cinode->lock_sem);
296 list_add(&fdlocks->llist, &cinode->llist);
297 up_write(&cinode->lock_sem);
298
299 cfile->count = 1;
300 cfile->pid = current->tgid;
301 cfile->uid = current_fsuid();
302 cfile->dentry = dget(dentry);
303 cfile->f_flags = file->f_flags;
304 cfile->invalidHandle = false;
305 cfile->tlink = cifs_get_tlink(tlink);
306 INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
307 mutex_init(&cfile->fh_mutex);
308 spin_lock_init(&cfile->file_info_lock);
309
310 cifs_sb_active(inode->i_sb);
311
312 /*
313 * If the server returned a read oplock and we have mandatory brlocks,
314 * set oplock level to None.
315 */
316 if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
317 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
318 oplock = 0;
319 }
320
321 spin_lock(&tcon->open_file_lock);
322 if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
323 oplock = fid->pending_open->oplock;
324 list_del(&fid->pending_open->olist);
325
326 fid->purge_cache = false;
327 server->ops->set_fid(cfile, fid, oplock);
328
329 list_add(&cfile->tlist, &tcon->openFileList);
330
331 /* if readable file instance put first in list*/
332 if (file->f_mode & FMODE_READ)
333 list_add(&cfile->flist, &cinode->openFileList);
334 else
335 list_add_tail(&cfile->flist, &cinode->openFileList);
336 spin_unlock(&tcon->open_file_lock);
337
338 if (fid->purge_cache)
339 cifs_zap_mapping(inode);
340
341 file->private_data = cfile;
342 return cfile;
343 }
344
345 struct cifsFileInfo *
346 cifsFileInfo_get(struct cifsFileInfo *cifs_file)
347 {
348 spin_lock(&cifs_file->file_info_lock);
349 cifsFileInfo_get_locked(cifs_file);
350 spin_unlock(&cifs_file->file_info_lock);
351 return cifs_file;
352 }
353
354 /*
355 * Release a reference on the file private data. This may involve closing
356 * the filehandle out on the server. Must be called without holding
357 * tcon->open_file_lock and cifs_file->file_info_lock.
358 */
359 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
360 {
361 struct inode *inode = d_inode(cifs_file->dentry);
362 struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
363 struct TCP_Server_Info *server = tcon->ses->server;
364 struct cifsInodeInfo *cifsi = CIFS_I(inode);
365 struct super_block *sb = inode->i_sb;
366 struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
367 struct cifsLockInfo *li, *tmp;
368 struct cifs_fid fid;
369 struct cifs_pending_open open;
370 bool oplock_break_cancelled;
371
372 spin_lock(&tcon->open_file_lock);
373
374 spin_lock(&cifs_file->file_info_lock);
375 if (--cifs_file->count > 0) {
376 spin_unlock(&cifs_file->file_info_lock);
377 spin_unlock(&tcon->open_file_lock);
378 return;
379 }
380 spin_unlock(&cifs_file->file_info_lock);
381
382 if (server->ops->get_lease_key)
383 server->ops->get_lease_key(inode, &fid);
384
385 /* store open in pending opens to make sure we don't miss lease break */
386 cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
387
388 /* remove it from the lists */
389 list_del(&cifs_file->flist);
390 list_del(&cifs_file->tlist);
391
392 if (list_empty(&cifsi->openFileList)) {
393 cifs_dbg(FYI, "closing last open instance for inode %p\n",
394 d_inode(cifs_file->dentry));
395 /*
396 * In strict cache mode we need invalidate mapping on the last
397 * close because it may cause a error when we open this file
398 * again and get at least level II oplock.
399 */
400 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
401 set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
402 cifs_set_oplock_level(cifsi, 0);
403 }
404
405 spin_unlock(&tcon->open_file_lock);
406
407 oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
408
409 if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
410 struct TCP_Server_Info *server = tcon->ses->server;
411 unsigned int xid;
412
413 xid = get_xid();
414 if (server->ops->close)
415 server->ops->close(xid, tcon, &cifs_file->fid);
416 _free_xid(xid);
417 }
418
419 if (oplock_break_cancelled)
420 cifs_done_oplock_break(cifsi);
421
422 cifs_del_pending_open(&open);
423
424 /*
425 * Delete any outstanding lock records. We'll lose them when the file
426 * is closed anyway.
427 */
428 down_write(&cifsi->lock_sem);
429 list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
430 list_del(&li->llist);
431 cifs_del_lock_waiters(li);
432 kfree(li);
433 }
434 list_del(&cifs_file->llist->llist);
435 kfree(cifs_file->llist);
436 up_write(&cifsi->lock_sem);
437
438 cifs_put_tlink(cifs_file->tlink);
439 dput(cifs_file->dentry);
440 cifs_sb_deactive(sb);
441 kfree(cifs_file);
442 }
443
444 int cifs_open(struct inode *inode, struct file *file)
445
446 {
447 int rc = -EACCES;
448 unsigned int xid;
449 __u32 oplock;
450 struct cifs_sb_info *cifs_sb;
451 struct TCP_Server_Info *server;
452 struct cifs_tcon *tcon;
453 struct tcon_link *tlink;
454 struct cifsFileInfo *cfile = NULL;
455 char *full_path = NULL;
456 bool posix_open_ok = false;
457 struct cifs_fid fid;
458 struct cifs_pending_open open;
459
460 xid = get_xid();
461
462 cifs_sb = CIFS_SB(inode->i_sb);
463 tlink = cifs_sb_tlink(cifs_sb);
464 if (IS_ERR(tlink)) {
465 free_xid(xid);
466 return PTR_ERR(tlink);
467 }
468 tcon = tlink_tcon(tlink);
469 server = tcon->ses->server;
470
471 full_path = build_path_from_dentry(file_dentry(file));
472 if (full_path == NULL) {
473 rc = -ENOMEM;
474 goto out;
475 }
476
477 cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
478 inode, file->f_flags, full_path);
479
480 if (file->f_flags & O_DIRECT &&
481 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
482 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
483 file->f_op = &cifs_file_direct_nobrl_ops;
484 else
485 file->f_op = &cifs_file_direct_ops;
486 }
487
488 if (server->oplocks)
489 oplock = REQ_OPLOCK;
490 else
491 oplock = 0;
492
493 if (!tcon->broken_posix_open && tcon->unix_ext &&
494 cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
495 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
496 /* can not refresh inode info since size could be stale */
497 rc = cifs_posix_open(full_path, &inode, inode->i_sb,
498 cifs_sb->mnt_file_mode /* ignored */,
499 file->f_flags, &oplock, &fid.netfid, xid);
500 if (rc == 0) {
501 cifs_dbg(FYI, "posix open succeeded\n");
502 posix_open_ok = true;
503 } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
504 if (tcon->ses->serverNOS)
505 cifs_dbg(VFS, "server %s of type %s returned unexpected error on SMB posix open, disabling posix open support. Check if server update available.\n",
506 tcon->ses->serverName,
507 tcon->ses->serverNOS);
508 tcon->broken_posix_open = true;
509 } else if ((rc != -EIO) && (rc != -EREMOTE) &&
510 (rc != -EOPNOTSUPP)) /* path not found or net err */
511 goto out;
512 /*
513 * Else fallthrough to retry open the old way on network i/o
514 * or DFS errors.
515 */
516 }
517
518 if (server->ops->get_lease_key)
519 server->ops->get_lease_key(inode, &fid);
520
521 cifs_add_pending_open(&fid, tlink, &open);
522
523 if (!posix_open_ok) {
524 if (server->ops->get_lease_key)
525 server->ops->get_lease_key(inode, &fid);
526
527 rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
528 file->f_flags, &oplock, &fid, xid);
529 if (rc) {
530 cifs_del_pending_open(&open);
531 goto out;
532 }
533 }
534
535 cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
536 if (cfile == NULL) {
537 if (server->ops->close)
538 server->ops->close(xid, tcon, &fid);
539 cifs_del_pending_open(&open);
540 rc = -ENOMEM;
541 goto out;
542 }
543
544 cifs_fscache_set_inode_cookie(inode, file);
545
546 if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) {
547 /*
548 * Time to set mode which we can not set earlier due to
549 * problems creating new read-only files.
550 */
551 struct cifs_unix_set_info_args args = {
552 .mode = inode->i_mode,
553 .uid = INVALID_UID, /* no change */
554 .gid = INVALID_GID, /* no change */
555 .ctime = NO_CHANGE_64,
556 .atime = NO_CHANGE_64,
557 .mtime = NO_CHANGE_64,
558 .device = 0,
559 };
560 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
561 cfile->pid);
562 }
563
564 out:
565 kfree(full_path);
566 free_xid(xid);
567 cifs_put_tlink(tlink);
568 return rc;
569 }
570
571 static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
572
573 /*
574 * Try to reacquire byte range locks that were released when session
575 * to server was lost.
576 */
577 static int
578 cifs_relock_file(struct cifsFileInfo *cfile)
579 {
580 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
581 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
582 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
583 int rc = 0;
584
585 down_read(&cinode->lock_sem);
586 if (cinode->can_cache_brlcks) {
587 /* can cache locks - no need to relock */
588 up_read(&cinode->lock_sem);
589 return rc;
590 }
591
592 if (cap_unix(tcon->ses) &&
593 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
594 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
595 rc = cifs_push_posix_locks(cfile);
596 else
597 rc = tcon->ses->server->ops->push_mand_locks(cfile);
598
599 up_read(&cinode->lock_sem);
600 return rc;
601 }
602
603 static int
604 cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
605 {
606 int rc = -EACCES;
607 unsigned int xid;
608 __u32 oplock;
609 struct cifs_sb_info *cifs_sb;
610 struct cifs_tcon *tcon;
611 struct TCP_Server_Info *server;
612 struct cifsInodeInfo *cinode;
613 struct inode *inode;
614 char *full_path = NULL;
615 int desired_access;
616 int disposition = FILE_OPEN;
617 int create_options = CREATE_NOT_DIR;
618 struct cifs_open_parms oparms;
619
620 xid = get_xid();
621 mutex_lock(&cfile->fh_mutex);
622 if (!cfile->invalidHandle) {
623 mutex_unlock(&cfile->fh_mutex);
624 rc = 0;
625 free_xid(xid);
626 return rc;
627 }
628
629 inode = d_inode(cfile->dentry);
630 cifs_sb = CIFS_SB(inode->i_sb);
631 tcon = tlink_tcon(cfile->tlink);
632 server = tcon->ses->server;
633
634 /*
635 * Can not grab rename sem here because various ops, including those
636 * that already have the rename sem can end up causing writepage to get
637 * called and if the server was down that means we end up here, and we
638 * can never tell if the caller already has the rename_sem.
639 */
640 full_path = build_path_from_dentry(cfile->dentry);
641 if (full_path == NULL) {
642 rc = -ENOMEM;
643 mutex_unlock(&cfile->fh_mutex);
644 free_xid(xid);
645 return rc;
646 }
647
648 cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
649 inode, cfile->f_flags, full_path);
650
651 if (tcon->ses->server->oplocks)
652 oplock = REQ_OPLOCK;
653 else
654 oplock = 0;
655
656 if (tcon->unix_ext && cap_unix(tcon->ses) &&
657 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
658 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
659 /*
660 * O_CREAT, O_EXCL and O_TRUNC already had their effect on the
661 * original open. Must mask them off for a reopen.
662 */
663 unsigned int oflags = cfile->f_flags &
664 ~(O_CREAT | O_EXCL | O_TRUNC);
665
666 rc = cifs_posix_open(full_path, NULL, inode->i_sb,
667 cifs_sb->mnt_file_mode /* ignored */,
668 oflags, &oplock, &cfile->fid.netfid, xid);
669 if (rc == 0) {
670 cifs_dbg(FYI, "posix reopen succeeded\n");
671 oparms.reconnect = true;
672 goto reopen_success;
673 }
674 /*
675 * fallthrough to retry open the old way on errors, especially
676 * in the reconnect path it is important to retry hard
677 */
678 }
679
680 desired_access = cifs_convert_flags(cfile->f_flags);
681
682 if (backup_cred(cifs_sb))
683 create_options |= CREATE_OPEN_BACKUP_INTENT;
684
685 if (server->ops->get_lease_key)
686 server->ops->get_lease_key(inode, &cfile->fid);
687
688 oparms.tcon = tcon;
689 oparms.cifs_sb = cifs_sb;
690 oparms.desired_access = desired_access;
691 oparms.create_options = create_options;
692 oparms.disposition = disposition;
693 oparms.path = full_path;
694 oparms.fid = &cfile->fid;
695 oparms.reconnect = true;
696
697 /*
698 * Can not refresh inode by passing in file_info buf to be returned by
699 * ops->open and then calling get_inode_info with returned buf since
700 * file might have write behind data that needs to be flushed and server
701 * version of file size can be stale. If we knew for sure that inode was
702 * not dirty locally we could do this.
703 */
704 rc = server->ops->open(xid, &oparms, &oplock, NULL);
705 if (rc == -ENOENT && oparms.reconnect == false) {
706 /* durable handle timeout is expired - open the file again */
707 rc = server->ops->open(xid, &oparms, &oplock, NULL);
708 /* indicate that we need to relock the file */
709 oparms.reconnect = true;
710 }
711
712 if (rc) {
713 mutex_unlock(&cfile->fh_mutex);
714 cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
715 cifs_dbg(FYI, "oplock: %d\n", oplock);
716 goto reopen_error_exit;
717 }
718
719 reopen_success:
720 cfile->invalidHandle = false;
721 mutex_unlock(&cfile->fh_mutex);
722 cinode = CIFS_I(inode);
723
724 if (can_flush) {
725 rc = filemap_write_and_wait(inode->i_mapping);
726 mapping_set_error(inode->i_mapping, rc);
727
728 if (tcon->unix_ext)
729 rc = cifs_get_inode_info_unix(&inode, full_path,
730 inode->i_sb, xid);
731 else
732 rc = cifs_get_inode_info(&inode, full_path, NULL,
733 inode->i_sb, xid, NULL);
734 }
735 /*
736 * Else we are writing out data to server already and could deadlock if
737 * we tried to flush data, and since we do not know if we have data that
738 * would invalidate the current end of file on the server we can not go
739 * to the server to get the new inode info.
740 */
741
742 /*
743 * If the server returned a read oplock and we have mandatory brlocks,
744 * set oplock level to None.
745 */
746 if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
747 cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
748 oplock = 0;
749 }
750
751 server->ops->set_fid(cfile, &cfile->fid, oplock);
752 if (oparms.reconnect)
753 cifs_relock_file(cfile);
754
755 reopen_error_exit:
756 kfree(full_path);
757 free_xid(xid);
758 return rc;
759 }
760
761 int cifs_close(struct inode *inode, struct file *file)
762 {
763 if (file->private_data != NULL) {
764 cifsFileInfo_put(file->private_data);
765 file->private_data = NULL;
766 }
767
768 /* return code from the ->release op is always ignored */
769 return 0;
770 }
771
772 void
773 cifs_reopen_persistent_handles(struct cifs_tcon *tcon)
774 {
775 struct cifsFileInfo *open_file;
776 struct list_head *tmp;
777 struct list_head *tmp1;
778 struct list_head tmp_list;
779
780 if (!tcon->use_persistent || !tcon->need_reopen_files)
781 return;
782
783 tcon->need_reopen_files = false;
784
785 cifs_dbg(FYI, "Reopen persistent handles");
786 INIT_LIST_HEAD(&tmp_list);
787
788 /* list all files open on tree connection, reopen resilient handles */
789 spin_lock(&tcon->open_file_lock);
790 list_for_each(tmp, &tcon->openFileList) {
791 open_file = list_entry(tmp, struct cifsFileInfo, tlist);
792 if (!open_file->invalidHandle)
793 continue;
794 cifsFileInfo_get(open_file);
795 list_add_tail(&open_file->rlist, &tmp_list);
796 }
797 spin_unlock(&tcon->open_file_lock);
798
799 list_for_each_safe(tmp, tmp1, &tmp_list) {
800 open_file = list_entry(tmp, struct cifsFileInfo, rlist);
801 if (cifs_reopen_file(open_file, false /* do not flush */))
802 tcon->need_reopen_files = true;
803 list_del_init(&open_file->rlist);
804 cifsFileInfo_put(open_file);
805 }
806 }
807
808 int cifs_closedir(struct inode *inode, struct file *file)
809 {
810 int rc = 0;
811 unsigned int xid;
812 struct cifsFileInfo *cfile = file->private_data;
813 struct cifs_tcon *tcon;
814 struct TCP_Server_Info *server;
815 char *buf;
816
817 cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
818
819 if (cfile == NULL)
820 return rc;
821
822 xid = get_xid();
823 tcon = tlink_tcon(cfile->tlink);
824 server = tcon->ses->server;
825
826 cifs_dbg(FYI, "Freeing private data in close dir\n");
827 spin_lock(&cfile->file_info_lock);
828 if (server->ops->dir_needs_close(cfile)) {
829 cfile->invalidHandle = true;
830 spin_unlock(&cfile->file_info_lock);
831 if (server->ops->close_dir)
832 rc = server->ops->close_dir(xid, tcon, &cfile->fid);
833 else
834 rc = -ENOSYS;
835 cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
836 /* not much we can do if it fails anyway, ignore rc */
837 rc = 0;
838 } else
839 spin_unlock(&cfile->file_info_lock);
840
841 buf = cfile->srch_inf.ntwrk_buf_start;
842 if (buf) {
843 cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
844 cfile->srch_inf.ntwrk_buf_start = NULL;
845 if (cfile->srch_inf.smallBuf)
846 cifs_small_buf_release(buf);
847 else
848 cifs_buf_release(buf);
849 }
850
851 cifs_put_tlink(cfile->tlink);
852 kfree(file->private_data);
853 file->private_data = NULL;
854 /* BB can we lock the filestruct while this is going on? */
855 free_xid(xid);
856 return rc;
857 }
858
859 static struct cifsLockInfo *
860 cifs_lock_init(__u64 offset, __u64 length, __u8 type)
861 {
862 struct cifsLockInfo *lock =
863 kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
864 if (!lock)
865 return lock;
866 lock->offset = offset;
867 lock->length = length;
868 lock->type = type;
869 lock->pid = current->tgid;
870 INIT_LIST_HEAD(&lock->blist);
871 init_waitqueue_head(&lock->block_q);
872 return lock;
873 }
874
875 void
876 cifs_del_lock_waiters(struct cifsLockInfo *lock)
877 {
878 struct cifsLockInfo *li, *tmp;
879 list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
880 list_del_init(&li->blist);
881 wake_up(&li->block_q);
882 }
883 }
884
885 #define CIFS_LOCK_OP 0
886 #define CIFS_READ_OP 1
887 #define CIFS_WRITE_OP 2
888
889 /* @rw_check : 0 - no op, 1 - read, 2 - write */
890 static bool
891 cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
892 __u64 length, __u8 type, struct cifsFileInfo *cfile,
893 struct cifsLockInfo **conf_lock, int rw_check)
894 {
895 struct cifsLockInfo *li;
896 struct cifsFileInfo *cur_cfile = fdlocks->cfile;
897 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
898
899 list_for_each_entry(li, &fdlocks->locks, llist) {
900 if (offset + length <= li->offset ||
901 offset >= li->offset + li->length)
902 continue;
903 if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
904 server->ops->compare_fids(cfile, cur_cfile)) {
905 /* shared lock prevents write op through the same fid */
906 if (!(li->type & server->vals->shared_lock_type) ||
907 rw_check != CIFS_WRITE_OP)
908 continue;
909 }
910 if ((type & server->vals->shared_lock_type) &&
911 ((server->ops->compare_fids(cfile, cur_cfile) &&
912 current->tgid == li->pid) || type == li->type))
913 continue;
914 if (conf_lock)
915 *conf_lock = li;
916 return true;
917 }
918 return false;
919 }
920
921 bool
922 cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
923 __u8 type, struct cifsLockInfo **conf_lock,
924 int rw_check)
925 {
926 bool rc = false;
927 struct cifs_fid_locks *cur;
928 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
929
930 list_for_each_entry(cur, &cinode->llist, llist) {
931 rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
932 cfile, conf_lock, rw_check);
933 if (rc)
934 break;
935 }
936
937 return rc;
938 }
939
940 /*
941 * Check if there is another lock that prevents us to set the lock (mandatory
942 * style). If such a lock exists, update the flock structure with its
943 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
944 * or leave it the same if we can't. Returns 0 if we don't need to request to
945 * the server or 1 otherwise.
946 */
947 static int
948 cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
949 __u8 type, struct file_lock *flock)
950 {
951 int rc = 0;
952 struct cifsLockInfo *conf_lock;
953 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
954 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
955 bool exist;
956
957 down_read(&cinode->lock_sem);
958
959 exist = cifs_find_lock_conflict(cfile, offset, length, type,
960 &conf_lock, CIFS_LOCK_OP);
961 if (exist) {
962 flock->fl_start = conf_lock->offset;
963 flock->fl_end = conf_lock->offset + conf_lock->length - 1;
964 flock->fl_pid = conf_lock->pid;
965 if (conf_lock->type & server->vals->shared_lock_type)
966 flock->fl_type = F_RDLCK;
967 else
968 flock->fl_type = F_WRLCK;
969 } else if (!cinode->can_cache_brlcks)
970 rc = 1;
971 else
972 flock->fl_type = F_UNLCK;
973
974 up_read(&cinode->lock_sem);
975 return rc;
976 }
977
978 static void
979 cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
980 {
981 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
982 down_write(&cinode->lock_sem);
983 list_add_tail(&lock->llist, &cfile->llist->locks);
984 up_write(&cinode->lock_sem);
985 }
986
987 /*
988 * Set the byte-range lock (mandatory style). Returns:
989 * 1) 0, if we set the lock and don't need to request to the server;
990 * 2) 1, if no locks prevent us but we need to request to the server;
991 * 3) -EACCESS, if there is a lock that prevents us and wait is false.
992 */
993 static int
994 cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
995 bool wait)
996 {
997 struct cifsLockInfo *conf_lock;
998 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
999 bool exist;
1000 int rc = 0;
1001
1002 try_again:
1003 exist = false;
1004 down_write(&cinode->lock_sem);
1005
1006 exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
1007 lock->type, &conf_lock, CIFS_LOCK_OP);
1008 if (!exist && cinode->can_cache_brlcks) {
1009 list_add_tail(&lock->llist, &cfile->llist->locks);
1010 up_write(&cinode->lock_sem);
1011 return rc;
1012 }
1013
1014 if (!exist)
1015 rc = 1;
1016 else if (!wait)
1017 rc = -EACCES;
1018 else {
1019 list_add_tail(&lock->blist, &conf_lock->blist);
1020 up_write(&cinode->lock_sem);
1021 rc = wait_event_interruptible(lock->block_q,
1022 (lock->blist.prev == &lock->blist) &&
1023 (lock->blist.next == &lock->blist));
1024 if (!rc)
1025 goto try_again;
1026 down_write(&cinode->lock_sem);
1027 list_del_init(&lock->blist);
1028 }
1029
1030 up_write(&cinode->lock_sem);
1031 return rc;
1032 }
1033
1034 /*
1035 * Check if there is another lock that prevents us to set the lock (posix
1036 * style). If such a lock exists, update the flock structure with its
1037 * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
1038 * or leave it the same if we can't. Returns 0 if we don't need to request to
1039 * the server or 1 otherwise.
1040 */
1041 static int
1042 cifs_posix_lock_test(struct file *file, struct file_lock *flock)
1043 {
1044 int rc = 0;
1045 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1046 unsigned char saved_type = flock->fl_type;
1047
1048 if ((flock->fl_flags & FL_POSIX) == 0)
1049 return 1;
1050
1051 down_read(&cinode->lock_sem);
1052 posix_test_lock(file, flock);
1053
1054 if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
1055 flock->fl_type = saved_type;
1056 rc = 1;
1057 }
1058
1059 up_read(&cinode->lock_sem);
1060 return rc;
1061 }
1062
1063 /*
1064 * Set the byte-range lock (posix style). Returns:
1065 * 1) 0, if we set the lock and don't need to request to the server;
1066 * 2) 1, if we need to request to the server;
1067 * 3) <0, if the error occurs while setting the lock.
1068 */
1069 static int
1070 cifs_posix_lock_set(struct file *file, struct file_lock *flock)
1071 {
1072 struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
1073 int rc = 1;
1074
1075 if ((flock->fl_flags & FL_POSIX) == 0)
1076 return rc;
1077
1078 try_again:
1079 down_write(&cinode->lock_sem);
1080 if (!cinode->can_cache_brlcks) {
1081 up_write(&cinode->lock_sem);
1082 return rc;
1083 }
1084
1085 rc = posix_lock_file(file, flock, NULL);
1086 up_write(&cinode->lock_sem);
1087 if (rc == FILE_LOCK_DEFERRED) {
1088 rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
1089 if (!rc)
1090 goto try_again;
1091 posix_unblock_lock(flock);
1092 }
1093 return rc;
1094 }
1095
1096 int
1097 cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
1098 {
1099 unsigned int xid;
1100 int rc = 0, stored_rc;
1101 struct cifsLockInfo *li, *tmp;
1102 struct cifs_tcon *tcon;
1103 unsigned int num, max_num, max_buf;
1104 LOCKING_ANDX_RANGE *buf, *cur;
1105 int types[] = {LOCKING_ANDX_LARGE_FILES,
1106 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1107 int i;
1108
1109 xid = get_xid();
1110 tcon = tlink_tcon(cfile->tlink);
1111
1112 /*
1113 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1114 * and check it for zero before using.
1115 */
1116 max_buf = tcon->ses->server->maxBuf;
1117 if (!max_buf) {
1118 free_xid(xid);
1119 return -EINVAL;
1120 }
1121
1122 max_num = (max_buf - sizeof(struct smb_hdr)) /
1123 sizeof(LOCKING_ANDX_RANGE);
1124 buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1125 if (!buf) {
1126 free_xid(xid);
1127 return -ENOMEM;
1128 }
1129
1130 for (i = 0; i < 2; i++) {
1131 cur = buf;
1132 num = 0;
1133 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1134 if (li->type != types[i])
1135 continue;
1136 cur->Pid = cpu_to_le16(li->pid);
1137 cur->LengthLow = cpu_to_le32((u32)li->length);
1138 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1139 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1140 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1141 if (++num == max_num) {
1142 stored_rc = cifs_lockv(xid, tcon,
1143 cfile->fid.netfid,
1144 (__u8)li->type, 0, num,
1145 buf);
1146 if (stored_rc)
1147 rc = stored_rc;
1148 cur = buf;
1149 num = 0;
1150 } else
1151 cur++;
1152 }
1153
1154 if (num) {
1155 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1156 (__u8)types[i], 0, num, buf);
1157 if (stored_rc)
1158 rc = stored_rc;
1159 }
1160 }
1161
1162 kfree(buf);
1163 free_xid(xid);
1164 return rc;
1165 }
1166
1167 static __u32
1168 hash_lockowner(fl_owner_t owner)
1169 {
1170 return cifs_lock_secret ^ hash32_ptr((const void *)owner);
1171 }
1172
1173 struct lock_to_push {
1174 struct list_head llist;
1175 __u64 offset;
1176 __u64 length;
1177 __u32 pid;
1178 __u16 netfid;
1179 __u8 type;
1180 };
1181
1182 static int
1183 cifs_push_posix_locks(struct cifsFileInfo *cfile)
1184 {
1185 struct inode *inode = d_inode(cfile->dentry);
1186 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1187 struct file_lock *flock;
1188 struct file_lock_context *flctx = inode->i_flctx;
1189 unsigned int count = 0, i;
1190 int rc = 0, xid, type;
1191 struct list_head locks_to_send, *el;
1192 struct lock_to_push *lck, *tmp;
1193 __u64 length;
1194
1195 xid = get_xid();
1196
1197 if (!flctx)
1198 goto out;
1199
1200 spin_lock(&flctx->flc_lock);
1201 list_for_each(el, &flctx->flc_posix) {
1202 count++;
1203 }
1204 spin_unlock(&flctx->flc_lock);
1205
1206 INIT_LIST_HEAD(&locks_to_send);
1207
1208 /*
1209 * Allocating count locks is enough because no FL_POSIX locks can be
1210 * added to the list while we are holding cinode->lock_sem that
1211 * protects locking operations of this inode.
1212 */
1213 for (i = 0; i < count; i++) {
1214 lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL);
1215 if (!lck) {
1216 rc = -ENOMEM;
1217 goto err_out;
1218 }
1219 list_add_tail(&lck->llist, &locks_to_send);
1220 }
1221
1222 el = locks_to_send.next;
1223 spin_lock(&flctx->flc_lock);
1224 list_for_each_entry(flock, &flctx->flc_posix, fl_list) {
1225 if (el == &locks_to_send) {
1226 /*
1227 * The list ended. We don't have enough allocated
1228 * structures - something is really wrong.
1229 */
1230 cifs_dbg(VFS, "Can't push all brlocks!\n");
1231 break;
1232 }
1233 length = 1 + flock->fl_end - flock->fl_start;
1234 if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
1235 type = CIFS_RDLCK;
1236 else
1237 type = CIFS_WRLCK;
1238 lck = list_entry(el, struct lock_to_push, llist);
1239 lck->pid = hash_lockowner(flock->fl_owner);
1240 lck->netfid = cfile->fid.netfid;
1241 lck->length = length;
1242 lck->type = type;
1243 lck->offset = flock->fl_start;
1244 }
1245 spin_unlock(&flctx->flc_lock);
1246
1247 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1248 int stored_rc;
1249
1250 stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
1251 lck->offset, lck->length, NULL,
1252 lck->type, 0);
1253 if (stored_rc)
1254 rc = stored_rc;
1255 list_del(&lck->llist);
1256 kfree(lck);
1257 }
1258
1259 out:
1260 free_xid(xid);
1261 return rc;
1262 err_out:
1263 list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
1264 list_del(&lck->llist);
1265 kfree(lck);
1266 }
1267 goto out;
1268 }
1269
1270 static int
1271 cifs_push_locks(struct cifsFileInfo *cfile)
1272 {
1273 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
1274 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1275 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1276 int rc = 0;
1277
1278 /* we are going to update can_cache_brlcks here - need a write access */
1279 down_write(&cinode->lock_sem);
1280 if (!cinode->can_cache_brlcks) {
1281 up_write(&cinode->lock_sem);
1282 return rc;
1283 }
1284
1285 if (cap_unix(tcon->ses) &&
1286 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1287 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1288 rc = cifs_push_posix_locks(cfile);
1289 else
1290 rc = tcon->ses->server->ops->push_mand_locks(cfile);
1291
1292 cinode->can_cache_brlcks = false;
1293 up_write(&cinode->lock_sem);
1294 return rc;
1295 }
1296
1297 static void
1298 cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
1299 bool *wait_flag, struct TCP_Server_Info *server)
1300 {
1301 if (flock->fl_flags & FL_POSIX)
1302 cifs_dbg(FYI, "Posix\n");
1303 if (flock->fl_flags & FL_FLOCK)
1304 cifs_dbg(FYI, "Flock\n");
1305 if (flock->fl_flags & FL_SLEEP) {
1306 cifs_dbg(FYI, "Blocking lock\n");
1307 *wait_flag = true;
1308 }
1309 if (flock->fl_flags & FL_ACCESS)
1310 cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
1311 if (flock->fl_flags & FL_LEASE)
1312 cifs_dbg(FYI, "Lease on file - not implemented yet\n");
1313 if (flock->fl_flags &
1314 (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
1315 FL_ACCESS | FL_LEASE | FL_CLOSE)))
1316 cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
1317
1318 *type = server->vals->large_lock_type;
1319 if (flock->fl_type == F_WRLCK) {
1320 cifs_dbg(FYI, "F_WRLCK\n");
1321 *type |= server->vals->exclusive_lock_type;
1322 *lock = 1;
1323 } else if (flock->fl_type == F_UNLCK) {
1324 cifs_dbg(FYI, "F_UNLCK\n");
1325 *type |= server->vals->unlock_lock_type;
1326 *unlock = 1;
1327 /* Check if unlock includes more than one lock range */
1328 } else if (flock->fl_type == F_RDLCK) {
1329 cifs_dbg(FYI, "F_RDLCK\n");
1330 *type |= server->vals->shared_lock_type;
1331 *lock = 1;
1332 } else if (flock->fl_type == F_EXLCK) {
1333 cifs_dbg(FYI, "F_EXLCK\n");
1334 *type |= server->vals->exclusive_lock_type;
1335 *lock = 1;
1336 } else if (flock->fl_type == F_SHLCK) {
1337 cifs_dbg(FYI, "F_SHLCK\n");
1338 *type |= server->vals->shared_lock_type;
1339 *lock = 1;
1340 } else
1341 cifs_dbg(FYI, "Unknown type of lock\n");
1342 }
1343
1344 static int
1345 cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
1346 bool wait_flag, bool posix_lck, unsigned int xid)
1347 {
1348 int rc = 0;
1349 __u64 length = 1 + flock->fl_end - flock->fl_start;
1350 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1351 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1352 struct TCP_Server_Info *server = tcon->ses->server;
1353 __u16 netfid = cfile->fid.netfid;
1354
1355 if (posix_lck) {
1356 int posix_lock_type;
1357
1358 rc = cifs_posix_lock_test(file, flock);
1359 if (!rc)
1360 return rc;
1361
1362 if (type & server->vals->shared_lock_type)
1363 posix_lock_type = CIFS_RDLCK;
1364 else
1365 posix_lock_type = CIFS_WRLCK;
1366 rc = CIFSSMBPosixLock(xid, tcon, netfid,
1367 hash_lockowner(flock->fl_owner),
1368 flock->fl_start, length, flock,
1369 posix_lock_type, wait_flag);
1370 return rc;
1371 }
1372
1373 rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
1374 if (!rc)
1375 return rc;
1376
1377 /* BB we could chain these into one lock request BB */
1378 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
1379 1, 0, false);
1380 if (rc == 0) {
1381 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1382 type, 0, 1, false);
1383 flock->fl_type = F_UNLCK;
1384 if (rc != 0)
1385 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1386 rc);
1387 return 0;
1388 }
1389
1390 if (type & server->vals->shared_lock_type) {
1391 flock->fl_type = F_WRLCK;
1392 return 0;
1393 }
1394
1395 type &= ~server->vals->exclusive_lock_type;
1396
1397 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1398 type | server->vals->shared_lock_type,
1399 1, 0, false);
1400 if (rc == 0) {
1401 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1402 type | server->vals->shared_lock_type, 0, 1, false);
1403 flock->fl_type = F_RDLCK;
1404 if (rc != 0)
1405 cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
1406 rc);
1407 } else
1408 flock->fl_type = F_WRLCK;
1409
1410 return 0;
1411 }
1412
1413 void
1414 cifs_move_llist(struct list_head *source, struct list_head *dest)
1415 {
1416 struct list_head *li, *tmp;
1417 list_for_each_safe(li, tmp, source)
1418 list_move(li, dest);
1419 }
1420
1421 void
1422 cifs_free_llist(struct list_head *llist)
1423 {
1424 struct cifsLockInfo *li, *tmp;
1425 list_for_each_entry_safe(li, tmp, llist, llist) {
1426 cifs_del_lock_waiters(li);
1427 list_del(&li->llist);
1428 kfree(li);
1429 }
1430 }
1431
1432 int
1433 cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
1434 unsigned int xid)
1435 {
1436 int rc = 0, stored_rc;
1437 int types[] = {LOCKING_ANDX_LARGE_FILES,
1438 LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
1439 unsigned int i;
1440 unsigned int max_num, num, max_buf;
1441 LOCKING_ANDX_RANGE *buf, *cur;
1442 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1443 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
1444 struct cifsLockInfo *li, *tmp;
1445 __u64 length = 1 + flock->fl_end - flock->fl_start;
1446 struct list_head tmp_llist;
1447
1448 INIT_LIST_HEAD(&tmp_llist);
1449
1450 /*
1451 * Accessing maxBuf is racy with cifs_reconnect - need to store value
1452 * and check it for zero before using.
1453 */
1454 max_buf = tcon->ses->server->maxBuf;
1455 if (!max_buf)
1456 return -EINVAL;
1457
1458 max_num = (max_buf - sizeof(struct smb_hdr)) /
1459 sizeof(LOCKING_ANDX_RANGE);
1460 buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
1461 if (!buf)
1462 return -ENOMEM;
1463
1464 down_write(&cinode->lock_sem);
1465 for (i = 0; i < 2; i++) {
1466 cur = buf;
1467 num = 0;
1468 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
1469 if (flock->fl_start > li->offset ||
1470 (flock->fl_start + length) <
1471 (li->offset + li->length))
1472 continue;
1473 if (current->tgid != li->pid)
1474 continue;
1475 if (types[i] != li->type)
1476 continue;
1477 if (cinode->can_cache_brlcks) {
1478 /*
1479 * We can cache brlock requests - simply remove
1480 * a lock from the file's list.
1481 */
1482 list_del(&li->llist);
1483 cifs_del_lock_waiters(li);
1484 kfree(li);
1485 continue;
1486 }
1487 cur->Pid = cpu_to_le16(li->pid);
1488 cur->LengthLow = cpu_to_le32((u32)li->length);
1489 cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
1490 cur->OffsetLow = cpu_to_le32((u32)li->offset);
1491 cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
1492 /*
1493 * We need to save a lock here to let us add it again to
1494 * the file's list if the unlock range request fails on
1495 * the server.
1496 */
1497 list_move(&li->llist, &tmp_llist);
1498 if (++num == max_num) {
1499 stored_rc = cifs_lockv(xid, tcon,
1500 cfile->fid.netfid,
1501 li->type, num, 0, buf);
1502 if (stored_rc) {
1503 /*
1504 * We failed on the unlock range
1505 * request - add all locks from the tmp
1506 * list to the head of the file's list.
1507 */
1508 cifs_move_llist(&tmp_llist,
1509 &cfile->llist->locks);
1510 rc = stored_rc;
1511 } else
1512 /*
1513 * The unlock range request succeed -
1514 * free the tmp list.
1515 */
1516 cifs_free_llist(&tmp_llist);
1517 cur = buf;
1518 num = 0;
1519 } else
1520 cur++;
1521 }
1522 if (num) {
1523 stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
1524 types[i], num, 0, buf);
1525 if (stored_rc) {
1526 cifs_move_llist(&tmp_llist,
1527 &cfile->llist->locks);
1528 rc = stored_rc;
1529 } else
1530 cifs_free_llist(&tmp_llist);
1531 }
1532 }
1533
1534 up_write(&cinode->lock_sem);
1535 kfree(buf);
1536 return rc;
1537 }
1538
1539 static int
1540 cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
1541 bool wait_flag, bool posix_lck, int lock, int unlock,
1542 unsigned int xid)
1543 {
1544 int rc = 0;
1545 __u64 length = 1 + flock->fl_end - flock->fl_start;
1546 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
1547 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
1548 struct TCP_Server_Info *server = tcon->ses->server;
1549 struct inode *inode = d_inode(cfile->dentry);
1550
1551 if (posix_lck) {
1552 int posix_lock_type;
1553
1554 rc = cifs_posix_lock_set(file, flock);
1555 if (!rc || rc < 0)
1556 return rc;
1557
1558 if (type & server->vals->shared_lock_type)
1559 posix_lock_type = CIFS_RDLCK;
1560 else
1561 posix_lock_type = CIFS_WRLCK;
1562
1563 if (unlock == 1)
1564 posix_lock_type = CIFS_UNLCK;
1565
1566 rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
1567 hash_lockowner(flock->fl_owner),
1568 flock->fl_start, length,
1569 NULL, posix_lock_type, wait_flag);
1570 goto out;
1571 }
1572
1573 if (lock) {
1574 struct cifsLockInfo *lock;
1575
1576 lock = cifs_lock_init(flock->fl_start, length, type);
1577 if (!lock)
1578 return -ENOMEM;
1579
1580 rc = cifs_lock_add_if(cfile, lock, wait_flag);
1581 if (rc < 0) {
1582 kfree(lock);
1583 return rc;
1584 }
1585 if (!rc)
1586 goto out;
1587
1588 /*
1589 * Windows 7 server can delay breaking lease from read to None
1590 * if we set a byte-range lock on a file - break it explicitly
1591 * before sending the lock to the server to be sure the next
1592 * read won't conflict with non-overlapted locks due to
1593 * pagereading.
1594 */
1595 if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
1596 CIFS_CACHE_READ(CIFS_I(inode))) {
1597 cifs_zap_mapping(inode);
1598 cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
1599 inode);
1600 CIFS_I(inode)->oplock = 0;
1601 }
1602
1603 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
1604 type, 1, 0, wait_flag);
1605 if (rc) {
1606 kfree(lock);
1607 return rc;
1608 }
1609
1610 cifs_lock_add(cfile, lock);
1611 } else if (unlock)
1612 rc = server->ops->mand_unlock_range(cfile, flock, xid);
1613
1614 out:
1615 if (flock->fl_flags & FL_POSIX && !rc)
1616 rc = locks_lock_file_wait(file, flock);
1617 return rc;
1618 }
1619
1620 int cifs_lock(struct file *file, int cmd, struct file_lock *flock)
1621 {
1622 int rc, xid;
1623 int lock = 0, unlock = 0;
1624 bool wait_flag = false;
1625 bool posix_lck = false;
1626 struct cifs_sb_info *cifs_sb;
1627 struct cifs_tcon *tcon;
1628 struct cifsInodeInfo *cinode;
1629 struct cifsFileInfo *cfile;
1630 __u16 netfid;
1631 __u32 type;
1632
1633 rc = -EACCES;
1634 xid = get_xid();
1635
1636 cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
1637 cmd, flock->fl_flags, flock->fl_type,
1638 flock->fl_start, flock->fl_end);
1639
1640 cfile = (struct cifsFileInfo *)file->private_data;
1641 tcon = tlink_tcon(cfile->tlink);
1642
1643 cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
1644 tcon->ses->server);
1645
1646 cifs_sb = CIFS_FILE_SB(file);
1647 netfid = cfile->fid.netfid;
1648 cinode = CIFS_I(file_inode(file));
1649
1650 if (cap_unix(tcon->ses) &&
1651 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
1652 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
1653 posix_lck = true;
1654 /*
1655 * BB add code here to normalize offset and length to account for
1656 * negative length which we can not accept over the wire.
1657 */
1658 if (IS_GETLK(cmd)) {
1659 rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
1660 free_xid(xid);
1661 return rc;
1662 }
1663
1664 if (!lock && !unlock) {
1665 /*
1666 * if no lock or unlock then nothing to do since we do not
1667 * know what it is
1668 */
1669 free_xid(xid);
1670 return -EOPNOTSUPP;
1671 }
1672
1673 rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
1674 xid);
1675 free_xid(xid);
1676 return rc;
1677 }
1678
1679 /*
1680 * update the file size (if needed) after a write. Should be called with
1681 * the inode->i_lock held
1682 */
1683 void
1684 cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
1685 unsigned int bytes_written)
1686 {
1687 loff_t end_of_write = offset + bytes_written;
1688
1689 if (end_of_write > cifsi->server_eof)
1690 cifsi->server_eof = end_of_write;
1691 }
1692
1693 static ssize_t
1694 cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
1695 size_t write_size, loff_t *offset)
1696 {
1697 int rc = 0;
1698 unsigned int bytes_written = 0;
1699 unsigned int total_written;
1700 struct cifs_sb_info *cifs_sb;
1701 struct cifs_tcon *tcon;
1702 struct TCP_Server_Info *server;
1703 unsigned int xid;
1704 struct dentry *dentry = open_file->dentry;
1705 struct cifsInodeInfo *cifsi = CIFS_I(d_inode(dentry));
1706 struct cifs_io_parms io_parms;
1707
1708 cifs_sb = CIFS_SB(dentry->d_sb);
1709
1710 cifs_dbg(FYI, "write %zd bytes to offset %lld of %pd\n",
1711 write_size, *offset, dentry);
1712
1713 tcon = tlink_tcon(open_file->tlink);
1714 server = tcon->ses->server;
1715
1716 if (!server->ops->sync_write)
1717 return -ENOSYS;
1718
1719 xid = get_xid();
1720
1721 for (total_written = 0; write_size > total_written;
1722 total_written += bytes_written) {
1723 rc = -EAGAIN;
1724 while (rc == -EAGAIN) {
1725 struct kvec iov[2];
1726 unsigned int len;
1727
1728 if (open_file->invalidHandle) {
1729 /* we could deadlock if we called
1730 filemap_fdatawait from here so tell
1731 reopen_file not to flush data to
1732 server now */
1733 rc = cifs_reopen_file(open_file, false);
1734 if (rc != 0)
1735 break;
1736 }
1737
1738 len = min(server->ops->wp_retry_size(d_inode(dentry)),
1739 (unsigned int)write_size - total_written);
1740 /* iov[0] is reserved for smb header */
1741 iov[1].iov_base = (char *)write_data + total_written;
1742 iov[1].iov_len = len;
1743 io_parms.pid = pid;
1744 io_parms.tcon = tcon;
1745 io_parms.offset = *offset;
1746 io_parms.length = len;
1747 rc = server->ops->sync_write(xid, &open_file->fid,
1748 &io_parms, &bytes_written, iov, 1);
1749 }
1750 if (rc || (bytes_written == 0)) {
1751 if (total_written)
1752 break;
1753 else {
1754 free_xid(xid);
1755 return rc;
1756 }
1757 } else {
1758 spin_lock(&d_inode(dentry)->i_lock);
1759 cifs_update_eof(cifsi, *offset, bytes_written);
1760 spin_unlock(&d_inode(dentry)->i_lock);
1761 *offset += bytes_written;
1762 }
1763 }
1764
1765 cifs_stats_bytes_written(tcon, total_written);
1766
1767 if (total_written > 0) {
1768 spin_lock(&d_inode(dentry)->i_lock);
1769 if (*offset > d_inode(dentry)->i_size)
1770 i_size_write(d_inode(dentry), *offset);
1771 spin_unlock(&d_inode(dentry)->i_lock);
1772 }
1773 mark_inode_dirty_sync(d_inode(dentry));
1774 free_xid(xid);
1775 return total_written;
1776 }
1777
1778 struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
1779 bool fsuid_only)
1780 {
1781 struct cifsFileInfo *open_file = NULL;
1782 struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1783 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
1784
1785 /* only filter by fsuid on multiuser mounts */
1786 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1787 fsuid_only = false;
1788
1789 spin_lock(&tcon->open_file_lock);
1790 /* we could simply get the first_list_entry since write-only entries
1791 are always at the end of the list but since the first entry might
1792 have a close pending, we go through the whole list */
1793 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1794 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1795 continue;
1796 if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
1797 if (!open_file->invalidHandle) {
1798 /* found a good file */
1799 /* lock it so it will not be closed on us */
1800 cifsFileInfo_get(open_file);
1801 spin_unlock(&tcon->open_file_lock);
1802 return open_file;
1803 } /* else might as well continue, and look for
1804 another, or simply have the caller reopen it
1805 again rather than trying to fix this handle */
1806 } else /* write only file */
1807 break; /* write only files are last so must be done */
1808 }
1809 spin_unlock(&tcon->open_file_lock);
1810 return NULL;
1811 }
1812
1813 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
1814 bool fsuid_only)
1815 {
1816 struct cifsFileInfo *open_file, *inv_file = NULL;
1817 struct cifs_sb_info *cifs_sb;
1818 struct cifs_tcon *tcon;
1819 bool any_available = false;
1820 int rc;
1821 unsigned int refind = 0;
1822
1823 /* Having a null inode here (because mapping->host was set to zero by
1824 the VFS or MM) should not happen but we had reports of on oops (due to
1825 it being zero) during stress testcases so we need to check for it */
1826
1827 if (cifs_inode == NULL) {
1828 cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
1829 dump_stack();
1830 return NULL;
1831 }
1832
1833 cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
1834 tcon = cifs_sb_master_tcon(cifs_sb);
1835
1836 /* only filter by fsuid on multiuser mounts */
1837 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
1838 fsuid_only = false;
1839
1840 spin_lock(&tcon->open_file_lock);
1841 refind_writable:
1842 if (refind > MAX_REOPEN_ATT) {
1843 spin_unlock(&tcon->open_file_lock);
1844 return NULL;
1845 }
1846 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
1847 if (!any_available && open_file->pid != current->tgid)
1848 continue;
1849 if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
1850 continue;
1851 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
1852 if (!open_file->invalidHandle) {
1853 /* found a good writable file */
1854 cifsFileInfo_get(open_file);
1855 spin_unlock(&tcon->open_file_lock);
1856 return open_file;
1857 } else {
1858 if (!inv_file)
1859 inv_file = open_file;
1860 }
1861 }
1862 }
1863 /* couldn't find useable FH with same pid, try any available */
1864 if (!any_available) {
1865 any_available = true;
1866 goto refind_writable;
1867 }
1868
1869 if (inv_file) {
1870 any_available = false;
1871 cifsFileInfo_get(inv_file);
1872 }
1873
1874 spin_unlock(&tcon->open_file_lock);
1875
1876 if (inv_file) {
1877 rc = cifs_reopen_file(inv_file, false);
1878 if (!rc)
1879 return inv_file;
1880 else {
1881 spin_lock(&tcon->open_file_lock);
1882 list_move_tail(&inv_file->flist,
1883 &cifs_inode->openFileList);
1884 spin_unlock(&tcon->open_file_lock);
1885 cifsFileInfo_put(inv_file);
1886 ++refind;
1887 inv_file = NULL;
1888 spin_lock(&tcon->open_file_lock);
1889 goto refind_writable;
1890 }
1891 }
1892
1893 return NULL;
1894 }
1895
1896 static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
1897 {
1898 struct address_space *mapping = page->mapping;
1899 loff_t offset = (loff_t)page->index << PAGE_SHIFT;
1900 char *write_data;
1901 int rc = -EFAULT;
1902 int bytes_written = 0;
1903 struct inode *inode;
1904 struct cifsFileInfo *open_file;
1905
1906 if (!mapping || !mapping->host)
1907 return -EFAULT;
1908
1909 inode = page->mapping->host;
1910
1911 offset += (loff_t)from;
1912 write_data = kmap(page);
1913 write_data += from;
1914
1915 if ((to > PAGE_SIZE) || (from > to)) {
1916 kunmap(page);
1917 return -EIO;
1918 }
1919
1920 /* racing with truncate? */
1921 if (offset > mapping->host->i_size) {
1922 kunmap(page);
1923 return 0; /* don't care */
1924 }
1925
1926 /* check to make sure that we are not extending the file */
1927 if (mapping->host->i_size - offset < (loff_t)to)
1928 to = (unsigned)(mapping->host->i_size - offset);
1929
1930 open_file = find_writable_file(CIFS_I(mapping->host), false);
1931 if (open_file) {
1932 bytes_written = cifs_write(open_file, open_file->pid,
1933 write_data, to - from, &offset);
1934 cifsFileInfo_put(open_file);
1935 /* Does mm or vfs already set times? */
1936 inode->i_atime = inode->i_mtime = current_time(inode);
1937 if ((bytes_written > 0) && (offset))
1938 rc = 0;
1939 else if (bytes_written < 0)
1940 rc = bytes_written;
1941 } else {
1942 cifs_dbg(FYI, "No writeable filehandles for inode\n");
1943 rc = -EIO;
1944 }
1945
1946 kunmap(page);
1947 return rc;
1948 }
1949
1950 static struct cifs_writedata *
1951 wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
1952 pgoff_t end, pgoff_t *index,
1953 unsigned int *found_pages)
1954 {
1955 unsigned int nr_pages;
1956 struct page **pages;
1957 struct cifs_writedata *wdata;
1958
1959 wdata = cifs_writedata_alloc((unsigned int)tofind,
1960 cifs_writev_complete);
1961 if (!wdata)
1962 return NULL;
1963
1964 /*
1965 * find_get_pages_tag seems to return a max of 256 on each
1966 * iteration, so we must call it several times in order to
1967 * fill the array or the wsize is effectively limited to
1968 * 256 * PAGE_SIZE.
1969 */
1970 *found_pages = 0;
1971 pages = wdata->pages;
1972 do {
1973 nr_pages = find_get_pages_tag(mapping, index,
1974 PAGECACHE_TAG_DIRTY, tofind,
1975 pages);
1976 *found_pages += nr_pages;
1977 tofind -= nr_pages;
1978 pages += nr_pages;
1979 } while (nr_pages && tofind && *index <= end);
1980
1981 return wdata;
1982 }
1983
1984 static unsigned int
1985 wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
1986 struct address_space *mapping,
1987 struct writeback_control *wbc,
1988 pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
1989 {
1990 unsigned int nr_pages = 0, i;
1991 struct page *page;
1992
1993 for (i = 0; i < found_pages; i++) {
1994 page = wdata->pages[i];
1995 /*
1996 * At this point we hold neither mapping->tree_lock nor
1997 * lock on the page itself: the page may be truncated or
1998 * invalidated (changing page->mapping to NULL), or even
1999 * swizzled back from swapper_space to tmpfs file
2000 * mapping
2001 */
2002
2003 if (nr_pages == 0)
2004 lock_page(page);
2005 else if (!trylock_page(page))
2006 break;
2007
2008 if (unlikely(page->mapping != mapping)) {
2009 unlock_page(page);
2010 break;
2011 }
2012
2013 if (!wbc->range_cyclic && page->index > end) {
2014 *done = true;
2015 unlock_page(page);
2016 break;
2017 }
2018
2019 if (*next && (page->index != *next)) {
2020 /* Not next consecutive page */
2021 unlock_page(page);
2022 break;
2023 }
2024
2025 if (wbc->sync_mode != WB_SYNC_NONE)
2026 wait_on_page_writeback(page);
2027
2028 if (PageWriteback(page) ||
2029 !clear_page_dirty_for_io(page)) {
2030 unlock_page(page);
2031 break;
2032 }
2033
2034 /*
2035 * This actually clears the dirty bit in the radix tree.
2036 * See cifs_writepage() for more commentary.
2037 */
2038 set_page_writeback(page);
2039 if (page_offset(page) >= i_size_read(mapping->host)) {
2040 *done = true;
2041 unlock_page(page);
2042 end_page_writeback(page);
2043 break;
2044 }
2045
2046 wdata->pages[i] = page;
2047 *next = page->index + 1;
2048 ++nr_pages;
2049 }
2050
2051 /* reset index to refind any pages skipped */
2052 if (nr_pages == 0)
2053 *index = wdata->pages[0]->index + 1;
2054
2055 /* put any pages we aren't going to use */
2056 for (i = nr_pages; i < found_pages; i++) {
2057 put_page(wdata->pages[i]);
2058 wdata->pages[i] = NULL;
2059 }
2060
2061 return nr_pages;
2062 }
2063
2064 static int
2065 wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
2066 struct address_space *mapping, struct writeback_control *wbc)
2067 {
2068 int rc = 0;
2069 struct TCP_Server_Info *server;
2070 unsigned int i;
2071
2072 wdata->sync_mode = wbc->sync_mode;
2073 wdata->nr_pages = nr_pages;
2074 wdata->offset = page_offset(wdata->pages[0]);
2075 wdata->pagesz = PAGE_SIZE;
2076 wdata->tailsz = min(i_size_read(mapping->host) -
2077 page_offset(wdata->pages[nr_pages - 1]),
2078 (loff_t)PAGE_SIZE);
2079 wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
2080
2081 if (wdata->cfile != NULL)
2082 cifsFileInfo_put(wdata->cfile);
2083 wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
2084 if (!wdata->cfile) {
2085 cifs_dbg(VFS, "No writable handles for inode\n");
2086 rc = -EBADF;
2087 } else {
2088 wdata->pid = wdata->cfile->pid;
2089 server = tlink_tcon(wdata->cfile->tlink)->ses->server;
2090 rc = server->ops->async_writev(wdata, cifs_writedata_release);
2091 }
2092
2093 for (i = 0; i < nr_pages; ++i)
2094 unlock_page(wdata->pages[i]);
2095
2096 return rc;
2097 }
2098
2099 static int cifs_writepages(struct address_space *mapping,
2100 struct writeback_control *wbc)
2101 {
2102 struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
2103 struct TCP_Server_Info *server;
2104 bool done = false, scanned = false, range_whole = false;
2105 pgoff_t end, index;
2106 struct cifs_writedata *wdata;
2107 int rc = 0;
2108
2109 /*
2110 * If wsize is smaller than the page cache size, default to writing
2111 * one page at a time via cifs_writepage
2112 */
2113 if (cifs_sb->wsize < PAGE_SIZE)
2114 return generic_writepages(mapping, wbc);
2115
2116 if (wbc->range_cyclic) {
2117 index = mapping->writeback_index; /* Start from prev offset */
2118 end = -1;
2119 } else {
2120 index = wbc->range_start >> PAGE_SHIFT;
2121 end = wbc->range_end >> PAGE_SHIFT;
2122 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2123 range_whole = true;
2124 scanned = true;
2125 }
2126 server = cifs_sb_master_tcon(cifs_sb)->ses->server;
2127 retry:
2128 while (!done && index <= end) {
2129 unsigned int i, nr_pages, found_pages, wsize, credits;
2130 pgoff_t next = 0, tofind, saved_index = index;
2131
2132 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2133 &wsize, &credits);
2134 if (rc)
2135 break;
2136
2137 tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
2138
2139 wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
2140 &found_pages);
2141 if (!wdata) {
2142 rc = -ENOMEM;
2143 add_credits_and_wake_if(server, credits, 0);
2144 break;
2145 }
2146
2147 if (found_pages == 0) {
2148 kref_put(&wdata->refcount, cifs_writedata_release);
2149 add_credits_and_wake_if(server, credits, 0);
2150 break;
2151 }
2152
2153 nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
2154 end, &index, &next, &done);
2155
2156 /* nothing to write? */
2157 if (nr_pages == 0) {
2158 kref_put(&wdata->refcount, cifs_writedata_release);
2159 add_credits_and_wake_if(server, credits, 0);
2160 continue;
2161 }
2162
2163 wdata->credits = credits;
2164
2165 rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
2166
2167 /* send failure -- clean up the mess */
2168 if (rc != 0) {
2169 add_credits_and_wake_if(server, wdata->credits, 0);
2170 for (i = 0; i < nr_pages; ++i) {
2171 if (rc == -EAGAIN)
2172 redirty_page_for_writepage(wbc,
2173 wdata->pages[i]);
2174 else
2175 SetPageError(wdata->pages[i]);
2176 end_page_writeback(wdata->pages[i]);
2177 put_page(wdata->pages[i]);
2178 }
2179 if (rc != -EAGAIN)
2180 mapping_set_error(mapping, rc);
2181 }
2182 kref_put(&wdata->refcount, cifs_writedata_release);
2183
2184 if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
2185 index = saved_index;
2186 continue;
2187 }
2188
2189 wbc->nr_to_write -= nr_pages;
2190 if (wbc->nr_to_write <= 0)
2191 done = true;
2192
2193 index = next;
2194 }
2195
2196 if (!scanned && !done) {
2197 /*
2198 * We hit the last page and there is more work to be done: wrap
2199 * back to the start of the file
2200 */
2201 scanned = true;
2202 index = 0;
2203 goto retry;
2204 }
2205
2206 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2207 mapping->writeback_index = index;
2208
2209 return rc;
2210 }
2211
2212 static int
2213 cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
2214 {
2215 int rc;
2216 unsigned int xid;
2217
2218 xid = get_xid();
2219 /* BB add check for wbc flags */
2220 get_page(page);
2221 if (!PageUptodate(page))
2222 cifs_dbg(FYI, "ppw - page not up to date\n");
2223
2224 /*
2225 * Set the "writeback" flag, and clear "dirty" in the radix tree.
2226 *
2227 * A writepage() implementation always needs to do either this,
2228 * or re-dirty the page with "redirty_page_for_writepage()" in
2229 * the case of a failure.
2230 *
2231 * Just unlocking the page will cause the radix tree tag-bits
2232 * to fail to update with the state of the page correctly.
2233 */
2234 set_page_writeback(page);
2235 retry_write:
2236 rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
2237 if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL)
2238 goto retry_write;
2239 else if (rc == -EAGAIN)
2240 redirty_page_for_writepage(wbc, page);
2241 else if (rc != 0)
2242 SetPageError(page);
2243 else
2244 SetPageUptodate(page);
2245 end_page_writeback(page);
2246 put_page(page);
2247 free_xid(xid);
2248 return rc;
2249 }
2250
2251 static int cifs_writepage(struct page *page, struct writeback_control *wbc)
2252 {
2253 int rc = cifs_writepage_locked(page, wbc);
2254 unlock_page(page);
2255 return rc;
2256 }
2257
2258 static int cifs_write_end(struct file *file, struct address_space *mapping,
2259 loff_t pos, unsigned len, unsigned copied,
2260 struct page *page, void *fsdata)
2261 {
2262 int rc;
2263 struct inode *inode = mapping->host;
2264 struct cifsFileInfo *cfile = file->private_data;
2265 struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
2266 __u32 pid;
2267
2268 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2269 pid = cfile->pid;
2270 else
2271 pid = current->tgid;
2272
2273 cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
2274 page, pos, copied);
2275
2276 if (PageChecked(page)) {
2277 if (copied == len)
2278 SetPageUptodate(page);
2279 ClearPageChecked(page);
2280 } else if (!PageUptodate(page) && copied == PAGE_SIZE)
2281 SetPageUptodate(page);
2282
2283 if (!PageUptodate(page)) {
2284 char *page_data;
2285 unsigned offset = pos & (PAGE_SIZE - 1);
2286 unsigned int xid;
2287
2288 xid = get_xid();
2289 /* this is probably better than directly calling
2290 partialpage_write since in this function the file handle is
2291 known which we might as well leverage */
2292 /* BB check if anything else missing out of ppw
2293 such as updating last write time */
2294 page_data = kmap(page);
2295 rc = cifs_write(cfile, pid, page_data + offset, copied, &pos);
2296 /* if (rc < 0) should we set writebehind rc? */
2297 kunmap(page);
2298
2299 free_xid(xid);
2300 } else {
2301 rc = copied;
2302 pos += copied;
2303 set_page_dirty(page);
2304 }
2305
2306 if (rc > 0) {
2307 spin_lock(&inode->i_lock);
2308 if (pos > inode->i_size)
2309 i_size_write(inode, pos);
2310 spin_unlock(&inode->i_lock);
2311 }
2312
2313 unlock_page(page);
2314 put_page(page);
2315
2316 return rc;
2317 }
2318
2319 int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
2320 int datasync)
2321 {
2322 unsigned int xid;
2323 int rc = 0;
2324 struct cifs_tcon *tcon;
2325 struct TCP_Server_Info *server;
2326 struct cifsFileInfo *smbfile = file->private_data;
2327 struct inode *inode = file_inode(file);
2328 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2329
2330 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2331 if (rc)
2332 return rc;
2333 inode_lock(inode);
2334
2335 xid = get_xid();
2336
2337 cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2338 file, datasync);
2339
2340 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
2341 rc = cifs_zap_mapping(inode);
2342 if (rc) {
2343 cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
2344 rc = 0; /* don't care about it in fsync */
2345 }
2346 }
2347
2348 tcon = tlink_tcon(smbfile->tlink);
2349 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2350 server = tcon->ses->server;
2351 if (server->ops->flush)
2352 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2353 else
2354 rc = -ENOSYS;
2355 }
2356
2357 free_xid(xid);
2358 inode_unlock(inode);
2359 return rc;
2360 }
2361
2362 int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
2363 {
2364 unsigned int xid;
2365 int rc = 0;
2366 struct cifs_tcon *tcon;
2367 struct TCP_Server_Info *server;
2368 struct cifsFileInfo *smbfile = file->private_data;
2369 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
2370 struct inode *inode = file->f_mapping->host;
2371
2372 rc = filemap_write_and_wait_range(inode->i_mapping, start, end);
2373 if (rc)
2374 return rc;
2375 inode_lock(inode);
2376
2377 xid = get_xid();
2378
2379 cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
2380 file, datasync);
2381
2382 tcon = tlink_tcon(smbfile->tlink);
2383 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
2384 server = tcon->ses->server;
2385 if (server->ops->flush)
2386 rc = server->ops->flush(xid, tcon, &smbfile->fid);
2387 else
2388 rc = -ENOSYS;
2389 }
2390
2391 free_xid(xid);
2392 inode_unlock(inode);
2393 return rc;
2394 }
2395
2396 /*
2397 * As file closes, flush all cached write data for this inode checking
2398 * for write behind errors.
2399 */
2400 int cifs_flush(struct file *file, fl_owner_t id)
2401 {
2402 struct inode *inode = file_inode(file);
2403 int rc = 0;
2404
2405 if (file->f_mode & FMODE_WRITE)
2406 rc = filemap_write_and_wait(inode->i_mapping);
2407
2408 cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", inode, file, rc);
2409
2410 return rc;
2411 }
2412
2413 static int
2414 cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
2415 {
2416 int rc = 0;
2417 unsigned long i;
2418
2419 for (i = 0; i < num_pages; i++) {
2420 pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2421 if (!pages[i]) {
2422 /*
2423 * save number of pages we have already allocated and
2424 * return with ENOMEM error
2425 */
2426 num_pages = i;
2427 rc = -ENOMEM;
2428 break;
2429 }
2430 }
2431
2432 if (rc) {
2433 for (i = 0; i < num_pages; i++)
2434 put_page(pages[i]);
2435 }
2436 return rc;
2437 }
2438
2439 static inline
2440 size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
2441 {
2442 size_t num_pages;
2443 size_t clen;
2444
2445 clen = min_t(const size_t, len, wsize);
2446 num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
2447
2448 if (cur_len)
2449 *cur_len = clen;
2450
2451 return num_pages;
2452 }
2453
2454 static void
2455 cifs_uncached_writedata_release(struct kref *refcount)
2456 {
2457 int i;
2458 struct cifs_writedata *wdata = container_of(refcount,
2459 struct cifs_writedata, refcount);
2460
2461 for (i = 0; i < wdata->nr_pages; i++)
2462 put_page(wdata->pages[i]);
2463 cifs_writedata_release(refcount);
2464 }
2465
2466 static void
2467 cifs_uncached_writev_complete(struct work_struct *work)
2468 {
2469 struct cifs_writedata *wdata = container_of(work,
2470 struct cifs_writedata, work);
2471 struct inode *inode = d_inode(wdata->cfile->dentry);
2472 struct cifsInodeInfo *cifsi = CIFS_I(inode);
2473
2474 spin_lock(&inode->i_lock);
2475 cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
2476 if (cifsi->server_eof > inode->i_size)
2477 i_size_write(inode, cifsi->server_eof);
2478 spin_unlock(&inode->i_lock);
2479
2480 complete(&wdata->done);
2481
2482 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2483 }
2484
2485 static int
2486 wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
2487 size_t *len, unsigned long *num_pages)
2488 {
2489 size_t save_len, copied, bytes, cur_len = *len;
2490 unsigned long i, nr_pages = *num_pages;
2491
2492 save_len = cur_len;
2493 for (i = 0; i < nr_pages; i++) {
2494 bytes = min_t(const size_t, cur_len, PAGE_SIZE);
2495 copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
2496 cur_len -= copied;
2497 /*
2498 * If we didn't copy as much as we expected, then that
2499 * may mean we trod into an unmapped area. Stop copying
2500 * at that point. On the next pass through the big
2501 * loop, we'll likely end up getting a zero-length
2502 * write and bailing out of it.
2503 */
2504 if (copied < bytes)
2505 break;
2506 }
2507 cur_len = save_len - cur_len;
2508 *len = cur_len;
2509
2510 /*
2511 * If we have no data to send, then that probably means that
2512 * the copy above failed altogether. That's most likely because
2513 * the address in the iovec was bogus. Return -EFAULT and let
2514 * the caller free anything we allocated and bail out.
2515 */
2516 if (!cur_len)
2517 return -EFAULT;
2518
2519 /*
2520 * i + 1 now represents the number of pages we actually used in
2521 * the copy phase above.
2522 */
2523 *num_pages = i + 1;
2524 return 0;
2525 }
2526
2527 static int
2528 cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
2529 struct cifsFileInfo *open_file,
2530 struct cifs_sb_info *cifs_sb, struct list_head *wdata_list)
2531 {
2532 int rc = 0;
2533 size_t cur_len;
2534 unsigned long nr_pages, num_pages, i;
2535 struct cifs_writedata *wdata;
2536 struct iov_iter saved_from = *from;
2537 loff_t saved_offset = offset;
2538 pid_t pid;
2539 struct TCP_Server_Info *server;
2540
2541 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2542 pid = open_file->pid;
2543 else
2544 pid = current->tgid;
2545
2546 server = tlink_tcon(open_file->tlink)->ses->server;
2547
2548 do {
2549 unsigned int wsize, credits;
2550
2551 rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
2552 &wsize, &credits);
2553 if (rc)
2554 break;
2555
2556 nr_pages = get_numpages(wsize, len, &cur_len);
2557 wdata = cifs_writedata_alloc(nr_pages,
2558 cifs_uncached_writev_complete);
2559 if (!wdata) {
2560 rc = -ENOMEM;
2561 add_credits_and_wake_if(server, credits, 0);
2562 break;
2563 }
2564
2565 rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
2566 if (rc) {
2567 kfree(wdata);
2568 add_credits_and_wake_if(server, credits, 0);
2569 break;
2570 }
2571
2572 num_pages = nr_pages;
2573 rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
2574 if (rc) {
2575 for (i = 0; i < nr_pages; i++)
2576 put_page(wdata->pages[i]);
2577 kfree(wdata);
2578 add_credits_and_wake_if(server, credits, 0);
2579 break;
2580 }
2581
2582 /*
2583 * Bring nr_pages down to the number of pages we actually used,
2584 * and free any pages that we didn't use.
2585 */
2586 for ( ; nr_pages > num_pages; nr_pages--)
2587 put_page(wdata->pages[nr_pages - 1]);
2588
2589 wdata->sync_mode = WB_SYNC_ALL;
2590 wdata->nr_pages = nr_pages;
2591 wdata->offset = (__u64)offset;
2592 wdata->cfile = cifsFileInfo_get(open_file);
2593 wdata->pid = pid;
2594 wdata->bytes = cur_len;
2595 wdata->pagesz = PAGE_SIZE;
2596 wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
2597 wdata->credits = credits;
2598
2599 if (!wdata->cfile->invalidHandle ||
2600 !cifs_reopen_file(wdata->cfile, false))
2601 rc = server->ops->async_writev(wdata,
2602 cifs_uncached_writedata_release);
2603 if (rc) {
2604 add_credits_and_wake_if(server, wdata->credits, 0);
2605 kref_put(&wdata->refcount,
2606 cifs_uncached_writedata_release);
2607 if (rc == -EAGAIN) {
2608 *from = saved_from;
2609 iov_iter_advance(from, offset - saved_offset);
2610 continue;
2611 }
2612 break;
2613 }
2614
2615 list_add_tail(&wdata->list, wdata_list);
2616 offset += cur_len;
2617 len -= cur_len;
2618 } while (len > 0);
2619
2620 return rc;
2621 }
2622
2623 ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
2624 {
2625 struct file *file = iocb->ki_filp;
2626 ssize_t total_written = 0;
2627 struct cifsFileInfo *open_file;
2628 struct cifs_tcon *tcon;
2629 struct cifs_sb_info *cifs_sb;
2630 struct cifs_writedata *wdata, *tmp;
2631 struct list_head wdata_list;
2632 struct iov_iter saved_from = *from;
2633 int rc;
2634
2635 /*
2636 * BB - optimize the way when signing is disabled. We can drop this
2637 * extra memory-to-memory copying and use iovec buffers for constructing
2638 * write request.
2639 */
2640
2641 rc = generic_write_checks(iocb, from);
2642 if (rc <= 0)
2643 return rc;
2644
2645 INIT_LIST_HEAD(&wdata_list);
2646 cifs_sb = CIFS_FILE_SB(file);
2647 open_file = file->private_data;
2648 tcon = tlink_tcon(open_file->tlink);
2649
2650 if (!tcon->ses->server->ops->async_writev)
2651 return -ENOSYS;
2652
2653 rc = cifs_write_from_iter(iocb->ki_pos, iov_iter_count(from), from,
2654 open_file, cifs_sb, &wdata_list);
2655
2656 /*
2657 * If at least one write was successfully sent, then discard any rc
2658 * value from the later writes. If the other write succeeds, then
2659 * we'll end up returning whatever was written. If it fails, then
2660 * we'll get a new rc value from that.
2661 */
2662 if (!list_empty(&wdata_list))
2663 rc = 0;
2664
2665 /*
2666 * Wait for and collect replies for any successful sends in order of
2667 * increasing offset. Once an error is hit or we get a fatal signal
2668 * while waiting, then return without waiting for any more replies.
2669 */
2670 restart_loop:
2671 list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
2672 if (!rc) {
2673 /* FIXME: freezable too? */
2674 rc = wait_for_completion_killable(&wdata->done);
2675 if (rc)
2676 rc = -EINTR;
2677 else if (wdata->result)
2678 rc = wdata->result;
2679 else
2680 total_written += wdata->bytes;
2681
2682 /* resend call if it's a retryable error */
2683 if (rc == -EAGAIN) {
2684 struct list_head tmp_list;
2685 struct iov_iter tmp_from = saved_from;
2686
2687 INIT_LIST_HEAD(&tmp_list);
2688 list_del_init(&wdata->list);
2689
2690 iov_iter_advance(&tmp_from,
2691 wdata->offset - iocb->ki_pos);
2692
2693 rc = cifs_write_from_iter(wdata->offset,
2694 wdata->bytes, &tmp_from,
2695 open_file, cifs_sb, &tmp_list);
2696
2697 list_splice(&tmp_list, &wdata_list);
2698
2699 kref_put(&wdata->refcount,
2700 cifs_uncached_writedata_release);
2701 goto restart_loop;
2702 }
2703 }
2704 list_del_init(&wdata->list);
2705 kref_put(&wdata->refcount, cifs_uncached_writedata_release);
2706 }
2707
2708 if (unlikely(!total_written))
2709 return rc;
2710
2711 iocb->ki_pos += total_written;
2712 set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(file_inode(file))->flags);
2713 cifs_stats_bytes_written(tcon, total_written);
2714 return total_written;
2715 }
2716
2717 static ssize_t
2718 cifs_writev(struct kiocb *iocb, struct iov_iter *from)
2719 {
2720 struct file *file = iocb->ki_filp;
2721 struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
2722 struct inode *inode = file->f_mapping->host;
2723 struct cifsInodeInfo *cinode = CIFS_I(inode);
2724 struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
2725 ssize_t rc;
2726
2727 /*
2728 * We need to hold the sem to be sure nobody modifies lock list
2729 * with a brlock that prevents writing.
2730 */
2731 down_read(&cinode->lock_sem);
2732 inode_lock(inode);
2733
2734 rc = generic_write_checks(iocb, from);
2735 if (rc <= 0)
2736 goto out;
2737
2738 if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
2739 server->vals->exclusive_lock_type, NULL,
2740 CIFS_WRITE_OP))
2741 rc = __generic_file_write_iter(iocb, from);
2742 else
2743 rc = -EACCES;
2744 out:
2745 inode_unlock(inode);
2746
2747 if (rc > 0)
2748 rc = generic_write_sync(iocb, rc);
2749 up_read(&cinode->lock_sem);
2750 return rc;
2751 }
2752
2753 ssize_t
2754 cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
2755 {
2756 struct inode *inode = file_inode(iocb->ki_filp);
2757 struct cifsInodeInfo *cinode = CIFS_I(inode);
2758 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
2759 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
2760 iocb->ki_filp->private_data;
2761 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
2762 ssize_t written;
2763
2764 written = cifs_get_writer(cinode);
2765 if (written)
2766 return written;
2767
2768 if (CIFS_CACHE_WRITE(cinode)) {
2769 if (cap_unix(tcon->ses) &&
2770 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
2771 && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
2772 written = generic_file_write_iter(iocb, from);
2773 goto out;
2774 }
2775 written = cifs_writev(iocb, from);
2776 goto out;
2777 }
2778 /*
2779 * For non-oplocked files in strict cache mode we need to write the data
2780 * to the server exactly from the pos to pos+len-1 rather than flush all
2781 * affected pages because it may cause a error with mandatory locks on
2782 * these pages but not on the region from pos to ppos+len-1.
2783 */
2784 written = cifs_user_writev(iocb, from);
2785 if (written > 0 && CIFS_CACHE_READ(cinode)) {
2786 /*
2787 * Windows 7 server can delay breaking level2 oplock if a write
2788 * request comes - break it on the client to prevent reading
2789 * an old data.
2790 */
2791 cifs_zap_mapping(inode);
2792 cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
2793 inode);
2794 cinode->oplock = 0;
2795 }
2796 out:
2797 cifs_put_writer(cinode);
2798 return written;
2799 }
2800
2801 static struct cifs_readdata *
2802 cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
2803 {
2804 struct cifs_readdata *rdata;
2805
2806 rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
2807 GFP_KERNEL);
2808 if (rdata != NULL) {
2809 kref_init(&rdata->refcount);
2810 INIT_LIST_HEAD(&rdata->list);
2811 init_completion(&rdata->done);
2812 INIT_WORK(&rdata->work, complete);
2813 }
2814
2815 return rdata;
2816 }
2817
2818 void
2819 cifs_readdata_release(struct kref *refcount)
2820 {
2821 struct cifs_readdata *rdata = container_of(refcount,
2822 struct cifs_readdata, refcount);
2823
2824 if (rdata->cfile)
2825 cifsFileInfo_put(rdata->cfile);
2826
2827 kfree(rdata);
2828 }
2829
2830 static int
2831 cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
2832 {
2833 int rc = 0;
2834 struct page *page;
2835 unsigned int i;
2836
2837 for (i = 0; i < nr_pages; i++) {
2838 page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
2839 if (!page) {
2840 rc = -ENOMEM;
2841 break;
2842 }
2843 rdata->pages[i] = page;
2844 }
2845
2846 if (rc) {
2847 for (i = 0; i < nr_pages; i++) {
2848 put_page(rdata->pages[i]);
2849 rdata->pages[i] = NULL;
2850 }
2851 }
2852 return rc;
2853 }
2854
2855 static void
2856 cifs_uncached_readdata_release(struct kref *refcount)
2857 {
2858 struct cifs_readdata *rdata = container_of(refcount,
2859 struct cifs_readdata, refcount);
2860 unsigned int i;
2861
2862 for (i = 0; i < rdata->nr_pages; i++) {
2863 put_page(rdata->pages[i]);
2864 rdata->pages[i] = NULL;
2865 }
2866 cifs_readdata_release(refcount);
2867 }
2868
2869 /**
2870 * cifs_readdata_to_iov - copy data from pages in response to an iovec
2871 * @rdata: the readdata response with list of pages holding data
2872 * @iter: destination for our data
2873 *
2874 * This function copies data from a list of pages in a readdata response into
2875 * an array of iovecs. It will first calculate where the data should go
2876 * based on the info in the readdata and then copy the data into that spot.
2877 */
2878 static int
2879 cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
2880 {
2881 size_t remaining = rdata->got_bytes;
2882 unsigned int i;
2883
2884 for (i = 0; i < rdata->nr_pages; i++) {
2885 struct page *page = rdata->pages[i];
2886 size_t copy = min_t(size_t, remaining, PAGE_SIZE);
2887 size_t written = copy_page_to_iter(page, 0, copy, iter);
2888 remaining -= written;
2889 if (written < copy && iov_iter_count(iter) > 0)
2890 break;
2891 }
2892 return remaining ? -EFAULT : 0;
2893 }
2894
2895 static void
2896 cifs_uncached_readv_complete(struct work_struct *work)
2897 {
2898 struct cifs_readdata *rdata = container_of(work,
2899 struct cifs_readdata, work);
2900
2901 complete(&rdata->done);
2902 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
2903 }
2904
2905 static int
2906 cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
2907 struct cifs_readdata *rdata, unsigned int len)
2908 {
2909 int result = 0;
2910 unsigned int i;
2911 unsigned int nr_pages = rdata->nr_pages;
2912
2913 rdata->got_bytes = 0;
2914 rdata->tailsz = PAGE_SIZE;
2915 for (i = 0; i < nr_pages; i++) {
2916 struct page *page = rdata->pages[i];
2917 size_t n;
2918
2919 if (len <= 0) {
2920 /* no need to hold page hostage */
2921 rdata->pages[i] = NULL;
2922 rdata->nr_pages--;
2923 put_page(page);
2924 continue;
2925 }
2926 n = len;
2927 if (len >= PAGE_SIZE) {
2928 /* enough data to fill the page */
2929 n = PAGE_SIZE;
2930 len -= n;
2931 } else {
2932 zero_user(page, len, PAGE_SIZE - len);
2933 rdata->tailsz = len;
2934 len = 0;
2935 }
2936 result = cifs_read_page_from_socket(server, page, n);
2937 if (result < 0)
2938 break;
2939
2940 rdata->got_bytes += result;
2941 }
2942
2943 return rdata->got_bytes > 0 && result != -ECONNABORTED ?
2944 rdata->got_bytes : result;
2945 }
2946
2947 static int
2948 cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
2949 struct cifs_sb_info *cifs_sb, struct list_head *rdata_list)
2950 {
2951 struct cifs_readdata *rdata;
2952 unsigned int npages, rsize, credits;
2953 size_t cur_len;
2954 int rc;
2955 pid_t pid;
2956 struct TCP_Server_Info *server;
2957
2958 server = tlink_tcon(open_file->tlink)->ses->server;
2959
2960 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
2961 pid = open_file->pid;
2962 else
2963 pid = current->tgid;
2964
2965 do {
2966 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
2967 &rsize, &credits);
2968 if (rc)
2969 break;
2970
2971 cur_len = min_t(const size_t, len, rsize);
2972 npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
2973
2974 /* allocate a readdata struct */
2975 rdata = cifs_readdata_alloc(npages,
2976 cifs_uncached_readv_complete);
2977 if (!rdata) {
2978 add_credits_and_wake_if(server, credits, 0);
2979 rc = -ENOMEM;
2980 break;
2981 }
2982
2983 rc = cifs_read_allocate_pages(rdata, npages);
2984 if (rc)
2985 goto error;
2986
2987 rdata->cfile = cifsFileInfo_get(open_file);
2988 rdata->nr_pages = npages;
2989 rdata->offset = offset;
2990 rdata->bytes = cur_len;
2991 rdata->pid = pid;
2992 rdata->pagesz = PAGE_SIZE;
2993 rdata->read_into_pages = cifs_uncached_read_into_pages;
2994 rdata->credits = credits;
2995
2996 if (!rdata->cfile->invalidHandle ||
2997 !cifs_reopen_file(rdata->cfile, true))
2998 rc = server->ops->async_readv(rdata);
2999 error:
3000 if (rc) {
3001 add_credits_and_wake_if(server, rdata->credits, 0);
3002 kref_put(&rdata->refcount,
3003 cifs_uncached_readdata_release);
3004 if (rc == -EAGAIN)
3005 continue;
3006 break;
3007 }
3008
3009 list_add_tail(&rdata->list, rdata_list);
3010 offset += cur_len;
3011 len -= cur_len;
3012 } while (len > 0);
3013
3014 return rc;
3015 }
3016
3017 ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
3018 {
3019 struct file *file = iocb->ki_filp;
3020 ssize_t rc;
3021 size_t len;
3022 ssize_t total_read = 0;
3023 loff_t offset = iocb->ki_pos;
3024 struct cifs_sb_info *cifs_sb;
3025 struct cifs_tcon *tcon;
3026 struct cifsFileInfo *open_file;
3027 struct cifs_readdata *rdata, *tmp;
3028 struct list_head rdata_list;
3029
3030 len = iov_iter_count(to);
3031 if (!len)
3032 return 0;
3033
3034 INIT_LIST_HEAD(&rdata_list);
3035 cifs_sb = CIFS_FILE_SB(file);
3036 open_file = file->private_data;
3037 tcon = tlink_tcon(open_file->tlink);
3038
3039 if (!tcon->ses->server->ops->async_readv)
3040 return -ENOSYS;
3041
3042 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3043 cifs_dbg(FYI, "attempting read on write only file instance\n");
3044
3045 rc = cifs_send_async_read(offset, len, open_file, cifs_sb, &rdata_list);
3046
3047 /* if at least one read request send succeeded, then reset rc */
3048 if (!list_empty(&rdata_list))
3049 rc = 0;
3050
3051 len = iov_iter_count(to);
3052 /* the loop below should proceed in the order of increasing offsets */
3053 again:
3054 list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
3055 if (!rc) {
3056 /* FIXME: freezable sleep too? */
3057 rc = wait_for_completion_killable(&rdata->done);
3058 if (rc)
3059 rc = -EINTR;
3060 else if (rdata->result == -EAGAIN) {
3061 /* resend call if it's a retryable error */
3062 struct list_head tmp_list;
3063 unsigned int got_bytes = rdata->got_bytes;
3064
3065 list_del_init(&rdata->list);
3066 INIT_LIST_HEAD(&tmp_list);
3067
3068 /*
3069 * Got a part of data and then reconnect has
3070 * happened -- fill the buffer and continue
3071 * reading.
3072 */
3073 if (got_bytes && got_bytes < rdata->bytes) {
3074 rc = cifs_readdata_to_iov(rdata, to);
3075 if (rc) {
3076 kref_put(&rdata->refcount,
3077 cifs_uncached_readdata_release);
3078 continue;
3079 }
3080 }
3081
3082 rc = cifs_send_async_read(
3083 rdata->offset + got_bytes,
3084 rdata->bytes - got_bytes,
3085 rdata->cfile, cifs_sb,
3086 &tmp_list);
3087
3088 list_splice(&tmp_list, &rdata_list);
3089
3090 kref_put(&rdata->refcount,
3091 cifs_uncached_readdata_release);
3092 goto again;
3093 } else if (rdata->result)
3094 rc = rdata->result;
3095 else
3096 rc = cifs_readdata_to_iov(rdata, to);
3097
3098 /* if there was a short read -- discard anything left */
3099 if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
3100 rc = -ENODATA;
3101 }
3102 list_del_init(&rdata->list);
3103 kref_put(&rdata->refcount, cifs_uncached_readdata_release);
3104 }
3105
3106 total_read = len - iov_iter_count(to);
3107
3108 cifs_stats_bytes_read(tcon, total_read);
3109
3110 /* mask nodata case */
3111 if (rc == -ENODATA)
3112 rc = 0;
3113
3114 if (total_read) {
3115 iocb->ki_pos += total_read;
3116 return total_read;
3117 }
3118 return rc;
3119 }
3120
3121 ssize_t
3122 cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
3123 {
3124 struct inode *inode = file_inode(iocb->ki_filp);
3125 struct cifsInodeInfo *cinode = CIFS_I(inode);
3126 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
3127 struct cifsFileInfo *cfile = (struct cifsFileInfo *)
3128 iocb->ki_filp->private_data;
3129 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3130 int rc = -EACCES;
3131
3132 /*
3133 * In strict cache mode we need to read from the server all the time
3134 * if we don't have level II oplock because the server can delay mtime
3135 * change - so we can't make a decision about inode invalidating.
3136 * And we can also fail with pagereading if there are mandatory locks
3137 * on pages affected by this read but not on the region from pos to
3138 * pos+len-1.
3139 */
3140 if (!CIFS_CACHE_READ(cinode))
3141 return cifs_user_readv(iocb, to);
3142
3143 if (cap_unix(tcon->ses) &&
3144 (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
3145 ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
3146 return generic_file_read_iter(iocb, to);
3147
3148 /*
3149 * We need to hold the sem to be sure nobody modifies lock list
3150 * with a brlock that prevents reading.
3151 */
3152 down_read(&cinode->lock_sem);
3153 if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
3154 tcon->ses->server->vals->shared_lock_type,
3155 NULL, CIFS_READ_OP))
3156 rc = generic_file_read_iter(iocb, to);
3157 up_read(&cinode->lock_sem);
3158 return rc;
3159 }
3160
3161 static ssize_t
3162 cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
3163 {
3164 int rc = -EACCES;
3165 unsigned int bytes_read = 0;
3166 unsigned int total_read;
3167 unsigned int current_read_size;
3168 unsigned int rsize;
3169 struct cifs_sb_info *cifs_sb;
3170 struct cifs_tcon *tcon;
3171 struct TCP_Server_Info *server;
3172 unsigned int xid;
3173 char *cur_offset;
3174 struct cifsFileInfo *open_file;
3175 struct cifs_io_parms io_parms;
3176 int buf_type = CIFS_NO_BUFFER;
3177 __u32 pid;
3178
3179 xid = get_xid();
3180 cifs_sb = CIFS_FILE_SB(file);
3181
3182 /* FIXME: set up handlers for larger reads and/or convert to async */
3183 rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
3184
3185 if (file->private_data == NULL) {
3186 rc = -EBADF;
3187 free_xid(xid);
3188 return rc;
3189 }
3190 open_file = file->private_data;
3191 tcon = tlink_tcon(open_file->tlink);
3192 server = tcon->ses->server;
3193
3194 if (!server->ops->sync_read) {
3195 free_xid(xid);
3196 return -ENOSYS;
3197 }
3198
3199 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3200 pid = open_file->pid;
3201 else
3202 pid = current->tgid;
3203
3204 if ((file->f_flags & O_ACCMODE) == O_WRONLY)
3205 cifs_dbg(FYI, "attempting read on write only file instance\n");
3206
3207 for (total_read = 0, cur_offset = read_data; read_size > total_read;
3208 total_read += bytes_read, cur_offset += bytes_read) {
3209 do {
3210 current_read_size = min_t(uint, read_size - total_read,
3211 rsize);
3212 /*
3213 * For windows me and 9x we do not want to request more
3214 * than it negotiated since it will refuse the read
3215 * then.
3216 */
3217 if ((tcon->ses) && !(tcon->ses->capabilities &
3218 tcon->ses->server->vals->cap_large_files)) {
3219 current_read_size = min_t(uint,
3220 current_read_size, CIFSMaxBufSize);
3221 }
3222 if (open_file->invalidHandle) {
3223 rc = cifs_reopen_file(open_file, true);
3224 if (rc != 0)
3225 break;
3226 }
3227 io_parms.pid = pid;
3228 io_parms.tcon = tcon;
3229 io_parms.offset = *offset;
3230 io_parms.length = current_read_size;
3231 rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
3232 &bytes_read, &cur_offset,
3233 &buf_type);
3234 } while (rc == -EAGAIN);
3235
3236 if (rc || (bytes_read == 0)) {
3237 if (total_read) {
3238 break;
3239 } else {
3240 free_xid(xid);
3241 return rc;
3242 }
3243 } else {
3244 cifs_stats_bytes_read(tcon, total_read);
3245 *offset += bytes_read;
3246 }
3247 }
3248 free_xid(xid);
3249 return total_read;
3250 }
3251
3252 /*
3253 * If the page is mmap'ed into a process' page tables, then we need to make
3254 * sure that it doesn't change while being written back.
3255 */
3256 static int
3257 cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
3258 {
3259 struct page *page = vmf->page;
3260
3261 lock_page(page);
3262 return VM_FAULT_LOCKED;
3263 }
3264
3265 static const struct vm_operations_struct cifs_file_vm_ops = {
3266 .fault = filemap_fault,
3267 .map_pages = filemap_map_pages,
3268 .page_mkwrite = cifs_page_mkwrite,
3269 };
3270
3271 int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma)
3272 {
3273 int rc, xid;
3274 struct inode *inode = file_inode(file);
3275
3276 xid = get_xid();
3277
3278 if (!CIFS_CACHE_READ(CIFS_I(inode))) {
3279 rc = cifs_zap_mapping(inode);
3280 if (rc)
3281 return rc;
3282 }
3283
3284 rc = generic_file_mmap(file, vma);
3285 if (rc == 0)
3286 vma->vm_ops = &cifs_file_vm_ops;
3287 free_xid(xid);
3288 return rc;
3289 }
3290
3291 int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
3292 {
3293 int rc, xid;
3294
3295 xid = get_xid();
3296 rc = cifs_revalidate_file(file);
3297 if (rc) {
3298 cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
3299 rc);
3300 free_xid(xid);
3301 return rc;
3302 }
3303 rc = generic_file_mmap(file, vma);
3304 if (rc == 0)
3305 vma->vm_ops = &cifs_file_vm_ops;
3306 free_xid(xid);
3307 return rc;
3308 }
3309
3310 static void
3311 cifs_readv_complete(struct work_struct *work)
3312 {
3313 unsigned int i, got_bytes;
3314 struct cifs_readdata *rdata = container_of(work,
3315 struct cifs_readdata, work);
3316
3317 got_bytes = rdata->got_bytes;
3318 for (i = 0; i < rdata->nr_pages; i++) {
3319 struct page *page = rdata->pages[i];
3320
3321 lru_cache_add_file(page);
3322
3323 if (rdata->result == 0 ||
3324 (rdata->result == -EAGAIN && got_bytes)) {
3325 flush_dcache_page(page);
3326 SetPageUptodate(page);
3327 }
3328
3329 unlock_page(page);
3330
3331 if (rdata->result == 0 ||
3332 (rdata->result == -EAGAIN && got_bytes))
3333 cifs_readpage_to_fscache(rdata->mapping->host, page);
3334
3335 got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
3336
3337 put_page(page);
3338 rdata->pages[i] = NULL;
3339 }
3340 kref_put(&rdata->refcount, cifs_readdata_release);
3341 }
3342
3343 static int
3344 cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
3345 struct cifs_readdata *rdata, unsigned int len)
3346 {
3347 int result = 0;
3348 unsigned int i;
3349 u64 eof;
3350 pgoff_t eof_index;
3351 unsigned int nr_pages = rdata->nr_pages;
3352
3353 /* determine the eof that the server (probably) has */
3354 eof = CIFS_I(rdata->mapping->host)->server_eof;
3355 eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0;
3356 cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
3357
3358 rdata->got_bytes = 0;
3359 rdata->tailsz = PAGE_SIZE;
3360 for (i = 0; i < nr_pages; i++) {
3361 struct page *page = rdata->pages[i];
3362 size_t n = PAGE_SIZE;
3363
3364 if (len >= PAGE_SIZE) {
3365 len -= PAGE_SIZE;
3366 } else if (len > 0) {
3367 /* enough for partial page, fill and zero the rest */
3368 zero_user(page, len, PAGE_SIZE - len);
3369 n = rdata->tailsz = len;
3370 len = 0;
3371 } else if (page->index > eof_index) {
3372 /*
3373 * The VFS will not try to do readahead past the
3374 * i_size, but it's possible that we have outstanding
3375 * writes with gaps in the middle and the i_size hasn't
3376 * caught up yet. Populate those with zeroed out pages
3377 * to prevent the VFS from repeatedly attempting to
3378 * fill them until the writes are flushed.
3379 */
3380 zero_user(page, 0, PAGE_SIZE);
3381 lru_cache_add_file(page);
3382 flush_dcache_page(page);
3383 SetPageUptodate(page);
3384 unlock_page(page);
3385 put_page(page);
3386 rdata->pages[i] = NULL;
3387 rdata->nr_pages--;
3388 continue;
3389 } else {
3390 /* no need to hold page hostage */
3391 lru_cache_add_file(page);
3392 unlock_page(page);
3393 put_page(page);
3394 rdata->pages[i] = NULL;
3395 rdata->nr_pages--;
3396 continue;
3397 }
3398
3399 result = cifs_read_page_from_socket(server, page, n);
3400 if (result < 0)
3401 break;
3402
3403 rdata->got_bytes += result;
3404 }
3405
3406 return rdata->got_bytes > 0 && result != -ECONNABORTED ?
3407 rdata->got_bytes : result;
3408 }
3409
3410 static int
3411 readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
3412 unsigned int rsize, struct list_head *tmplist,
3413 unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
3414 {
3415 struct page *page, *tpage;
3416 unsigned int expected_index;
3417 int rc;
3418 gfp_t gfp = readahead_gfp_mask(mapping);
3419
3420 INIT_LIST_HEAD(tmplist);
3421
3422 page = list_entry(page_list->prev, struct page, lru);
3423
3424 /*
3425 * Lock the page and put it in the cache. Since no one else
3426 * should have access to this page, we're safe to simply set
3427 * PG_locked without checking it first.
3428 */
3429 __SetPageLocked(page);
3430 rc = add_to_page_cache_locked(page, mapping,
3431 page->index, gfp);
3432
3433 /* give up if we can't stick it in the cache */
3434 if (rc) {
3435 __ClearPageLocked(page);
3436 return rc;
3437 }
3438
3439 /* move first page to the tmplist */
3440 *offset = (loff_t)page->index << PAGE_SHIFT;
3441 *bytes = PAGE_SIZE;
3442 *nr_pages = 1;
3443 list_move_tail(&page->lru, tmplist);
3444
3445 /* now try and add more pages onto the request */
3446 expected_index = page->index + 1;
3447 list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
3448 /* discontinuity ? */
3449 if (page->index != expected_index)
3450 break;
3451
3452 /* would this page push the read over the rsize? */
3453 if (*bytes + PAGE_SIZE > rsize)
3454 break;
3455
3456 __SetPageLocked(page);
3457 if (add_to_page_cache_locked(page, mapping, page->index, gfp)) {
3458 __ClearPageLocked(page);
3459 break;
3460 }
3461 list_move_tail(&page->lru, tmplist);
3462 (*bytes) += PAGE_SIZE;
3463 expected_index++;
3464 (*nr_pages)++;
3465 }
3466 return rc;
3467 }
3468
3469 static int cifs_readpages(struct file *file, struct address_space *mapping,
3470 struct list_head *page_list, unsigned num_pages)
3471 {
3472 int rc;
3473 struct list_head tmplist;
3474 struct cifsFileInfo *open_file = file->private_data;
3475 struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
3476 struct TCP_Server_Info *server;
3477 pid_t pid;
3478
3479 /*
3480 * Reads as many pages as possible from fscache. Returns -ENOBUFS
3481 * immediately if the cookie is negative
3482 *
3483 * After this point, every page in the list might have PG_fscache set,
3484 * so we will need to clean that up off of every page we don't use.
3485 */
3486 rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
3487 &num_pages);
3488 if (rc == 0)
3489 return rc;
3490
3491 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
3492 pid = open_file->pid;
3493 else
3494 pid = current->tgid;
3495
3496 rc = 0;
3497 server = tlink_tcon(open_file->tlink)->ses->server;
3498
3499 cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
3500 __func__, file, mapping, num_pages);
3501
3502 /*
3503 * Start with the page at end of list and move it to private
3504 * list. Do the same with any following pages until we hit
3505 * the rsize limit, hit an index discontinuity, or run out of
3506 * pages. Issue the async read and then start the loop again
3507 * until the list is empty.
3508 *
3509 * Note that list order is important. The page_list is in
3510 * the order of declining indexes. When we put the pages in
3511 * the rdata->pages, then we want them in increasing order.
3512 */
3513 while (!list_empty(page_list)) {
3514 unsigned int i, nr_pages, bytes, rsize;
3515 loff_t offset;
3516 struct page *page, *tpage;
3517 struct cifs_readdata *rdata;
3518 unsigned credits;
3519
3520 rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
3521 &rsize, &credits);
3522 if (rc)
3523 break;
3524
3525 /*
3526 * Give up immediately if rsize is too small to read an entire
3527 * page. The VFS will fall back to readpage. We should never
3528 * reach this point however since we set ra_pages to 0 when the
3529 * rsize is smaller than a cache page.
3530 */
3531 if (unlikely(rsize < PAGE_SIZE)) {
3532 add_credits_and_wake_if(server, credits, 0);
3533 return 0;
3534 }
3535
3536 rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
3537 &nr_pages, &offset, &bytes);
3538 if (rc) {
3539 add_credits_and_wake_if(server, credits, 0);
3540 break;
3541 }
3542
3543 rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
3544 if (!rdata) {
3545 /* best to give up if we're out of mem */
3546 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3547 list_del(&page->lru);
3548 lru_cache_add_file(page);
3549 unlock_page(page);
3550 put_page(page);
3551 }
3552 rc = -ENOMEM;
3553 add_credits_and_wake_if(server, credits, 0);
3554 break;
3555 }
3556
3557 rdata->cfile = cifsFileInfo_get(open_file);
3558 rdata->mapping = mapping;
3559 rdata->offset = offset;
3560 rdata->bytes = bytes;
3561 rdata->pid = pid;
3562 rdata->pagesz = PAGE_SIZE;
3563 rdata->read_into_pages = cifs_readpages_read_into_pages;
3564 rdata->credits = credits;
3565
3566 list_for_each_entry_safe(page, tpage, &tmplist, lru) {
3567 list_del(&page->lru);
3568 rdata->pages[rdata->nr_pages++] = page;
3569 }
3570
3571 if (!rdata->cfile->invalidHandle ||
3572 !cifs_reopen_file(rdata->cfile, true))
3573 rc = server->ops->async_readv(rdata);
3574 if (rc) {
3575 add_credits_and_wake_if(server, rdata->credits, 0);
3576 for (i = 0; i < rdata->nr_pages; i++) {
3577 page = rdata->pages[i];
3578 lru_cache_add_file(page);
3579 unlock_page(page);
3580 put_page(page);
3581 }
3582 /* Fallback to the readpage in error/reconnect cases */
3583 kref_put(&rdata->refcount, cifs_readdata_release);
3584 break;
3585 }
3586
3587 kref_put(&rdata->refcount, cifs_readdata_release);
3588 }
3589
3590 /* Any pages that have been shown to fscache but didn't get added to
3591 * the pagecache must be uncached before they get returned to the
3592 * allocator.
3593 */
3594 cifs_fscache_readpages_cancel(mapping->host, page_list);
3595 return rc;
3596 }
3597
3598 /*
3599 * cifs_readpage_worker must be called with the page pinned
3600 */
3601 static int cifs_readpage_worker(struct file *file, struct page *page,
3602 loff_t *poffset)
3603 {
3604 char *read_data;
3605 int rc;
3606
3607 /* Is the page cached? */
3608 rc = cifs_readpage_from_fscache(file_inode(file), page);
3609 if (rc == 0)
3610 goto read_complete;
3611
3612 read_data = kmap(page);
3613 /* for reads over a certain size could initiate async read ahead */
3614
3615 rc = cifs_read(file, read_data, PAGE_SIZE, poffset);
3616
3617 if (rc < 0)
3618 goto io_error;
3619 else
3620 cifs_dbg(FYI, "Bytes read %d\n", rc);
3621
3622 file_inode(file)->i_atime =
3623 current_time(file_inode(file));
3624
3625 if (PAGE_SIZE > rc)
3626 memset(read_data + rc, 0, PAGE_SIZE - rc);
3627
3628 flush_dcache_page(page);
3629 SetPageUptodate(page);
3630
3631 /* send this page to the cache */
3632 cifs_readpage_to_fscache(file_inode(file), page);
3633
3634 rc = 0;
3635
3636 io_error:
3637 kunmap(page);
3638 unlock_page(page);
3639
3640 read_complete:
3641 return rc;
3642 }
3643
3644 static int cifs_readpage(struct file *file, struct page *page)
3645 {
3646 loff_t offset = (loff_t)page->index << PAGE_SHIFT;
3647 int rc = -EACCES;
3648 unsigned int xid;
3649
3650 xid = get_xid();
3651
3652 if (file->private_data == NULL) {
3653 rc = -EBADF;
3654 free_xid(xid);
3655 return rc;
3656 }
3657
3658 cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
3659 page, (int)offset, (int)offset);
3660
3661 rc = cifs_readpage_worker(file, page, &offset);
3662
3663 free_xid(xid);
3664 return rc;
3665 }
3666
3667 static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
3668 {
3669 struct cifsFileInfo *open_file;
3670 struct cifs_tcon *tcon =
3671 cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb));
3672
3673 spin_lock(&tcon->open_file_lock);
3674 list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
3675 if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
3676 spin_unlock(&tcon->open_file_lock);
3677 return 1;
3678 }
3679 }
3680 spin_unlock(&tcon->open_file_lock);
3681 return 0;
3682 }
3683
3684 /* We do not want to update the file size from server for inodes
3685 open for write - to avoid races with writepage extending
3686 the file - in the future we could consider allowing
3687 refreshing the inode only on increases in the file size
3688 but this is tricky to do without racing with writebehind
3689 page caching in the current Linux kernel design */
3690 bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
3691 {
3692 if (!cifsInode)
3693 return true;
3694
3695 if (is_inode_writable(cifsInode)) {
3696 /* This inode is open for write at least once */
3697 struct cifs_sb_info *cifs_sb;
3698
3699 cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
3700 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
3701 /* since no page cache to corrupt on directio
3702 we can change size safely */
3703 return true;
3704 }
3705
3706 if (i_size_read(&cifsInode->vfs_inode) < end_of_file)
3707 return true;
3708
3709 return false;
3710 } else
3711 return true;
3712 }
3713
3714 static int cifs_write_begin(struct file *file, struct address_space *mapping,
3715 loff_t pos, unsigned len, unsigned flags,
3716 struct page **pagep, void **fsdata)
3717 {
3718 int oncethru = 0;
3719 pgoff_t index = pos >> PAGE_SHIFT;
3720 loff_t offset = pos & (PAGE_SIZE - 1);
3721 loff_t page_start = pos & PAGE_MASK;
3722 loff_t i_size;
3723 struct page *page;
3724 int rc = 0;
3725
3726 cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
3727
3728 start:
3729 page = grab_cache_page_write_begin(mapping, index, flags);
3730 if (!page) {
3731 rc = -ENOMEM;
3732 goto out;
3733 }
3734
3735 if (PageUptodate(page))
3736 goto out;
3737
3738 /*
3739 * If we write a full page it will be up to date, no need to read from
3740 * the server. If the write is short, we'll end up doing a sync write
3741 * instead.
3742 */
3743 if (len == PAGE_SIZE)
3744 goto out;
3745
3746 /*
3747 * optimize away the read when we have an oplock, and we're not
3748 * expecting to use any of the data we'd be reading in. That
3749 * is, when the page lies beyond the EOF, or straddles the EOF
3750 * and the write will cover all of the existing data.
3751 */
3752 if (CIFS_CACHE_READ(CIFS_I(mapping->host))) {
3753 i_size = i_size_read(mapping->host);
3754 if (page_start >= i_size ||
3755 (offset == 0 && (pos + len) >= i_size)) {
3756 zero_user_segments(page, 0, offset,
3757 offset + len,
3758 PAGE_SIZE);
3759 /*
3760 * PageChecked means that the parts of the page
3761 * to which we're not writing are considered up
3762 * to date. Once the data is copied to the
3763 * page, it can be set uptodate.
3764 */
3765 SetPageChecked(page);
3766 goto out;
3767 }
3768 }
3769
3770 if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
3771 /*
3772 * might as well read a page, it is fast enough. If we get
3773 * an error, we don't need to return it. cifs_write_end will
3774 * do a sync write instead since PG_uptodate isn't set.
3775 */
3776 cifs_readpage_worker(file, page, &page_start);
3777 put_page(page);
3778 oncethru = 1;
3779 goto start;
3780 } else {
3781 /* we could try using another file handle if there is one -
3782 but how would we lock it to prevent close of that handle
3783 racing with this read? In any case
3784 this will be written out by write_end so is fine */
3785 }
3786 out:
3787 *pagep = page;
3788 return rc;
3789 }
3790
3791 static int cifs_release_page(struct page *page, gfp_t gfp)
3792 {
3793 if (PagePrivate(page))
3794 return 0;
3795
3796 return cifs_fscache_release_page(page, gfp);
3797 }
3798
3799 static void cifs_invalidate_page(struct page *page, unsigned int offset,
3800 unsigned int length)
3801 {
3802 struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
3803
3804 if (offset == 0 && length == PAGE_SIZE)
3805 cifs_fscache_invalidate_page(page, &cifsi->vfs_inode);
3806 }
3807
3808 static int cifs_launder_page(struct page *page)
3809 {
3810 int rc = 0;
3811 loff_t range_start = page_offset(page);
3812 loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
3813 struct writeback_control wbc = {
3814 .sync_mode = WB_SYNC_ALL,
3815 .nr_to_write = 0,
3816 .range_start = range_start,
3817 .range_end = range_end,
3818 };
3819
3820 cifs_dbg(FYI, "Launder page: %p\n", page);
3821
3822 if (clear_page_dirty_for_io(page))
3823 rc = cifs_writepage_locked(page, &wbc);
3824
3825 cifs_fscache_invalidate_page(page, page->mapping->host);
3826 return rc;
3827 }
3828
3829 void cifs_oplock_break(struct work_struct *work)
3830 {
3831 struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
3832 oplock_break);
3833 struct inode *inode = d_inode(cfile->dentry);
3834 struct cifsInodeInfo *cinode = CIFS_I(inode);
3835 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
3836 struct TCP_Server_Info *server = tcon->ses->server;
3837 int rc = 0;
3838
3839 wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
3840 TASK_UNINTERRUPTIBLE);
3841
3842 server->ops->downgrade_oplock(server, cinode,
3843 test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
3844
3845 if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
3846 cifs_has_mand_locks(cinode)) {
3847 cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
3848 inode);
3849 cinode->oplock = 0;
3850 }
3851
3852 if (inode && S_ISREG(inode->i_mode)) {
3853 if (CIFS_CACHE_READ(cinode))
3854 break_lease(inode, O_RDONLY);
3855 else
3856 break_lease(inode, O_WRONLY);
3857 rc = filemap_fdatawrite(inode->i_mapping);
3858 if (!CIFS_CACHE_READ(cinode)) {
3859 rc = filemap_fdatawait(inode->i_mapping);
3860 mapping_set_error(inode->i_mapping, rc);
3861 cifs_zap_mapping(inode);
3862 }
3863 cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
3864 }
3865
3866 rc = cifs_push_locks(cfile);
3867 if (rc)
3868 cifs_dbg(VFS, "Push locks rc = %d\n", rc);
3869
3870 /*
3871 * releasing stale oplock after recent reconnect of smb session using
3872 * a now incorrect file handle is not a data integrity issue but do
3873 * not bother sending an oplock release if session to server still is
3874 * disconnected since oplock already released by the server
3875 */
3876 if (!cfile->oplock_break_cancelled) {
3877 rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
3878 cinode);
3879 cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
3880 }
3881 cifs_done_oplock_break(cinode);
3882 }
3883
3884 /*
3885 * The presence of cifs_direct_io() in the address space ops vector
3886 * allowes open() O_DIRECT flags which would have failed otherwise.
3887 *
3888 * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
3889 * so this method should never be called.
3890 *
3891 * Direct IO is not yet supported in the cached mode.
3892 */
3893 static ssize_t
3894 cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
3895 {
3896 /*
3897 * FIXME
3898 * Eventually need to support direct IO for non forcedirectio mounts
3899 */
3900 return -EINVAL;
3901 }
3902
3903
3904 const struct address_space_operations cifs_addr_ops = {
3905 .readpage = cifs_readpage,
3906 .readpages = cifs_readpages,
3907 .writepage = cifs_writepage,
3908 .writepages = cifs_writepages,
3909 .write_begin = cifs_write_begin,
3910 .write_end = cifs_write_end,
3911 .set_page_dirty = __set_page_dirty_nobuffers,
3912 .releasepage = cifs_release_page,
3913 .direct_IO = cifs_direct_io,
3914 .invalidatepage = cifs_invalidate_page,
3915 .launder_page = cifs_launder_page,
3916 };
3917
3918 /*
3919 * cifs_readpages requires the server to support a buffer large enough to
3920 * contain the header plus one complete page of data. Otherwise, we need
3921 * to leave cifs_readpages out of the address space operations.
3922 */
3923 const struct address_space_operations cifs_addr_ops_smallbuf = {
3924 .readpage = cifs_readpage,
3925 .writepage = cifs_writepage,
3926 .writepages = cifs_writepages,
3927 .write_begin = cifs_write_begin,
3928 .write_end = cifs_write_end,
3929 .set_page_dirty = __set_page_dirty_nobuffers,
3930 .releasepage = cifs_release_page,
3931 .invalidatepage = cifs_invalidate_page,
3932 .launder_page = cifs_launder_page,
3933 };
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